Publications by authors named "Natalia S Rost"

162 Publications

Radiomic signature of DWI-FLAIR mismatch in large vessel occlusion stroke.

J Neuroimaging 2021 Sep 10. Epub 2021 Sep 10.

Department of Neurosurgery, Massachusetts General Hospital, Boston, Massachusetts, USA.

Background And Purpose: Ischemic diffusion-weighted imaging-fluid-attenuated inversion recovery (DWI-FLAIR) mismatch may be useful in guiding acute stroke treatment decisions given its relationship to onset time and parenchymal viability; however, it relies on subjective grading. Radiomics is an emerging image quantification methodology that may objectively represent continuous image characteristics. We propose a novel radiomics approach to characterize DWI-FLAIR mismatch.

Methods: Ischemic lesions were visually graded for FLAIR positivity (absent, subtle, obvious) among consecutive large vessel occlusion stroke patients who underwent hyperacute MRI. Radiomic features were extracted from within the lesions on DWI and FLAIR. The DWI-FLAIR mismatch radiomics signature was built with features systematically selected by a cross-validated ElasticNet linear regression model of mismatch.

Results: We identified 103 patients with mean age 68 ± 16 years; 63% were female. FLAIR hyperintensity was absent in 25%, subtle in 55%, and obvious in 20%. Inter-rater agreement for visual grading was moderate (Κ = .58). The radiomics signature of DWI-FLAIR mismatch included native FLAIR histogram kurtosis and local binary pattern-filtered FLAIR gray-level cluster shade; both correlated with visual grading (ρ = -.42, p < .001 and ρ = .40, p < .001, respectively).

Conclusions: Radiomics can describe DWI-FLAIR mismatch and may provide objective, continuous biomarkers for infarct evolution using clinical-grade images. These novel biomarkers may prove useful for treatment decisions and future research.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/jon.12928DOI Listing
September 2021

Idiopathic primary intraventricular hemorrhage and cerebral small vessel disease.

Int J Stroke 2021 Sep 10:17474930211043957. Epub 2021 Sep 10.

Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.

Background: Although primary intraventricular hemorrhage is frequently due to trauma or vascular lesions, the etiology of idiopathic primary intraventricular hemorrhage (IP-IVH) is not defined.

Aims: Herein, we test the hypothesis that cerebral small vessel diseases (cSVD) including hypertensive cSVD (HTN-cSVD) and cerebral amyloid angiopathy are associated with IP-IVH.

Methods: Brain magnetic resonance imaging from consecutive patients (January 2011 to September 2019) with non-traumatic intracerebral hemorrhage from a single referral center were reviewed for the presence of HTN-cSVD (defined by strictly deep or mixed-location intracerebral hemorrhage/cerebral microbleeds) and cerebral amyloid angiopathy (applying modified Boston criteria).

Results: Forty-six (4%) out of 1276 patients were identified as having IP-IVH. Among these, the mean age was 74.4 ± 12.2 years and 18 (39%) were females. Forty (87%) had hypertension, and the mean initial blood pressure was 169.2 ± 40.4/88.8 ± 22.2 mmHg. Of the 35 (76%) patients who received a brain magnetic resonance imaging, two (6%) fulfilled the modified Boston criteria for possible cerebral amyloid angiopathy and 10 (29%) for probable cerebral amyloid angiopathy. Probable cerebral amyloid angiopathy was found at a similar frequency when comparing IP-IVH patients to the remaining patients with primary intraparenchymal hemorrhage (P-IPH) (27%,  = 0.85). Furthermore, imaging evidence for HTN-cSVD was found in 8 (24%) patients with IP-IVH compared to 209 (28%,  = 0.52) patients with P-IPH.

Conclusions: Among IP-IVH patients, cerebral amyloid angiopathy was found in approximately one-third of patients, whereas HTN-cSVD was detected in 23%-both similar rates to P-IPH patients. Our results suggest that both cSVD subtypes may be associated with IP-IVH.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/17474930211043957DOI Listing
September 2021

Therapeutic Anticoagulation with Heparin in Critically Ill Patients with Covid-19.

N Engl J Med 2021 Aug 4;385(9):777-789. Epub 2021 Aug 4.

From the University of Toronto (E.C.G., P.R.L., L.C.G., M.E.F., V.D., R.A.F., J.P.G., M.H., A.S.S.), University Health Network (E.C.G., M.H.), Peter Munk Cardiac Centre at University Health Network (P.R.L., L.C.G., M.E.F., V.D.), Ozmosis Research (L.B., V.W.), Sunnybrook Health Sciences Centre (J.P.G.), Toronto, Ottawa Hospital Research Institute (M. Carrier, L.A.C., D.A.F., G.L.G., D.M.S.), Institut du Savoir Montfort (M. Carrier, G.L.G.), and the University of Ottawa (L.A.C., D.A.F., D.M.S.), Ottawa, the University of Manitoba (A. Kumar, B.L.H., R.Z., S.A.L., D.S., G.V.-G.) and CancerCare Manitoba (B.L.H., R.Z.), Winnipeg, Université Laval and Centre Hospitalier Universitaire de Québec-Université Laval Research Center, Quebec, QC (A.F.T.), McGill University, Montreal (S.R.K., E.G.M.), St. Michael's Hospital Unity Health, Toronto (J.C.M., Z.B., M.S., A.S.S.), McMaster University and the Thrombosis and Atherosclerosis Research Institute, Hamilton, ON (P.L.G.) Université de Sherbrooke, Sherbrooke, QC (F.L.), St. Boniface Hospital, Winnipeg, MB (N.M.), the University of British Columbia, Vancouver (S. Murthy), and the University of Alberta, Edmonton (S.D.) - all in Canada; University of Bristol and University Hospitals Bristol and Weston NHS Foundation Trust, Bristol (C.A.B.), the London School of Hygiene and Tropical Medicine (B.-A.K.), Imperial College London (A.C.G., F.A.-B., M.A.L.), Imperial College Healthcare NHS Trust, St. Mary's Hospital (A.C.G.), University College London Hospital (R.H.), Kings Healthcare Partners (B.J.H.), and Intensive Care National Audit and Research Centre (ICNARC) (P.R.M., K.R.), London, Queen's University Belfast and Royal Victoria Hospital, Belfast (D.F.M.), and Oxford University (A. Beane, L.J.E., S.J.S.) and NHS Blood and Transplant (L.J.E., S. Mavromichalis, S.J.S.), Oxford - all in the United Kingdom; the University of Pittsburgh (B.J.M., D.C.A., M.M.B., M.D.N., H.F.E., J.D.F., Z.F., D.T.H., A.J.K., C.M.L., K.L., M.M., S.K.M., C.W.S., Y.Z.), University of Pittsburgh Medical Center (B.J.M., D.C.A., M.D.N., K.L.), the Clinical Research, Investigation, and Systems Modeling of Acute Illness (CRISMA) Center, University of Pittsburgh (T.D.G.), and University of Pittsburgh Medical Center Children's Hospital of Pittsburgh (C.M. Horvat) - all in Pittsburgh; New York University (NYU) Grossman School of Medicine (J.S.B., H.R.R., J.S.H., T.C., A.C., N.M.K., S. Mavromichalis, S.P.), NYU Langone Health, NYU Langone Hospital (T.A., T.C., A.C., J.M.H., E.Y.), and Bellevue Hospital (N.M.K.), Icahn School of Medicine at Mount Sinai (R.S.R.), and Mount Sinai Heart (R.S.R.), New York, Montefiore Medical Center (M.N.G., H.H.B., S.C., J.-T.C., A.A. Hope, R.N.) and Albert Einstein College of Medicine (M.N.G., H.H.B., B.T.G., A.A. Hope), Bronx, and NYU Langone Long Island, Mineola (A.A. Hindenburg) - all in New York; Zuckerberg San Francisco General Hospital-University of California, San Francisco (L.Z.K., C.M. Hendrickson, M.M.K., A.E.K., B.N.-G., J.J.P.), Harbor-UCLA Medical Center, Torrance (R.J.L.), Global Coalition for Adaptive Research (M. Buxton) and the University of California, Los Angeles (G.L.), Los Angeles, the University of California San Diego School of Medicine, San Diego (T.W.C.), and Stanford University School of Medicine, Palo Alto (J.G.W.) - all in California; the University of Illinois (K.S.K., J.R.J., J.G.Q.), the University of Chicago (J.D.P.), and the Chartis Group (J.S.) - all in Chicago; University Medical Center Utrecht, Utrecht University (L.P.G.D., M. Bonten, R.E.G.S., W.B.-P.), and Utrecht University (R.E.G.S.), Utrecht, and Radboud University Medical Center, Nijmegen (S. Middeldorp, F.L.V.) - all in the Netherlands; Larner College of Medicine at the University of Vermont, Burlington (M. Cushman); Inselspital, Bern University Hospital, University of Bern, Bern (T.T.), and SOCAR Research, Nyon (B.-A.K., S. Brouwer) - both in Switzerland; Instituto do Coracao, Hospital das Clinicas, Faculdade de Medicina, Universidade de Sao Paulo (L.C.G., F.G.L., J.C.N.), Avanti Pesquisa Clínica (A.S.M.), and Hospital 9 de Julho (F.O.S.), Sao Paulo, Hospital do Coração de Mato Grosso do Sul (M.P.), the Federal University of Mato Grosso do Sul (M.P.), Hospital Universitário Maria Aparecida Pedrossia (D.G.S.), and Hospital Unimed Campo Grande (D.G.S.), Campo Grande, and Instituto Goiano de Oncologia e Hematologia, Clinical Research Center, Goiânia (M.O.S.) - all in Brazil; the Australian and New Zealand Intensive Care Research Centre, Monash University (Z.M., C.J.M., S.A.W., A. Buzgau, C.G., A.M.H., S.P.M., A.D.N., J.C.P.), Monash University (A.C.C.), and Alfred Health (A.C.C., A.D.N.), Melbourne, VIC, St. John of God Subiaco Hospital, Subiaco, WA (S.A.W., E. Litton), Flinders University, Bedford Park, SA (S. Bihari), and Fiona Stanley Hospital, Perth, WA (E. Litton) - all in Australia; Berry Consultants, Austin (R.J.L., L.R.B., E. Lorenzi, S.M.B., M.A.D., M.F., A.M., C.T.S.), and Baylor Scott and White Health, Temple (R.J.W.) - both in Texas; Auckland City Hospital (C.J.M., S.P.M., R.L.P.) and the University of Auckland (R.L.P.), Auckland, and the Medical Research Institute of New Zealand, Wellington (C.J.M., A.M.T.) - all in New Zealand; Fédération Hospitalo-Universitaire Saclay and Paris Seine Nord Endeavour to Personalize Interventions for Sepsis (FHU-SEPSIS), Raymond Poincaré Hospital, Université de Versailles Saint-Quentin-en-Yvelines, Garches (D. Annane), and Aix-Marseille University, Marseille (B.C.) - both in France; King Saud bin Abdulaziz University for Health Sciences and King Abdullah International Medical Research Center, Riyadh, Kingdom of Saudi Arabia (Y.M.A.); Nepal Mediciti Hospital, Lalitpur (D. Aryal), and the Nepal Intensive Care Research Foundation, Kathmandu (D. Aryal); Versiti Blood Research Institute, Milwaukee (L.B.K.); National Intensive Care Surveillance (NICS)-Mahidol Oxford Tropical Medicine Research Unit (MORU), Colombo, Sri Lanka (A. Beane); Jena University Hospital, Jena, Germany (F.B.); Cleveland Clinic, Cleveland (A.D.), and the University of Cincinnati, Cincinnati (K.H.) - both in Ohio; Ochsner Medical Center, University of Queensland-Ochsner Clinical School, New Orleans (M.B.E.); Instituto Mexicano del Seguro Social, Mexico City (J.E., E.M.G.); Brigham and Women's Hospital (B.M.E., Y.K., S.M.H.), Massachusetts General Hospital (N.S.R., A.B.S.), and Harvard Medical School (B.M.E., Y.K., N.S.R., A.B.S.) - all in Boston; University of Alabama, Birmingham (S.G.); TriStar Centennial Medical Center, Nashville (A.L.G.); University of Antwerp, Wilrijk, Belgium (H.G.); Rutgers New Jersey Medical School, Newark, New Jersey (Y.Y.G.); University of Oxford, Bangkok, Thailand (R.H.); the University of Michigan, Ann Arbor (R.C.H., P.K.P.), Beaumont Health, Royal Oak (G.B.N.), and Oakland University William Beaumont School of Medicine, Auburn Hills (G.B.N.) - all in Michigan; Apollo Speciality Hospital OMR, Chennai, India (D.J.); Oregon Health and Science University, Portland (A. Khan); National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A. Kindzelski, E.S.L.); University of Mississippi Medical Center, Jackson (M.E.K.); IdiPaz Research Institute, Universidad Autonoma, Madrid (J.L.-S.); University College Dublin, Dublin (A.D.N.); the University of Kansas School of Medicine, Kansas City (L.S.); and Duke University Hospital, Durham, North Carolina (L.W.).

Background: Thrombosis and inflammation may contribute to morbidity and mortality among patients with coronavirus disease 2019 (Covid-19). We hypothesized that therapeutic-dose anticoagulation would improve outcomes in critically ill patients with Covid-19.

Methods: In an open-label, adaptive, multiplatform, randomized clinical trial, critically ill patients with severe Covid-19 were randomly assigned to a pragmatically defined regimen of either therapeutic-dose anticoagulation with heparin or pharmacologic thromboprophylaxis in accordance with local usual care. The primary outcome was organ support-free days, evaluated on an ordinal scale that combined in-hospital death (assigned a value of -1) and the number of days free of cardiovascular or respiratory organ support up to day 21 among patients who survived to hospital discharge.

Results: The trial was stopped when the prespecified criterion for futility was met for therapeutic-dose anticoagulation. Data on the primary outcome were available for 1098 patients (534 assigned to therapeutic-dose anticoagulation and 564 assigned to usual-care thromboprophylaxis). The median value for organ support-free days was 1 (interquartile range, -1 to 16) among the patients assigned to therapeutic-dose anticoagulation and was 4 (interquartile range, -1 to 16) among the patients assigned to usual-care thromboprophylaxis (adjusted proportional odds ratio, 0.83; 95% credible interval, 0.67 to 1.03; posterior probability of futility [defined as an odds ratio <1.2], 99.9%). The percentage of patients who survived to hospital discharge was similar in the two groups (62.7% and 64.5%, respectively; adjusted odds ratio, 0.84; 95% credible interval, 0.64 to 1.11). Major bleeding occurred in 3.8% of the patients assigned to therapeutic-dose anticoagulation and in 2.3% of those assigned to usual-care pharmacologic thromboprophylaxis.

Conclusions: In critically ill patients with Covid-19, an initial strategy of therapeutic-dose anticoagulation with heparin did not result in a greater probability of survival to hospital discharge or a greater number of days free of cardiovascular or respiratory organ support than did usual-care pharmacologic thromboprophylaxis. (REMAP-CAP, ACTIV-4a, and ATTACC ClinicalTrials.gov numbers, NCT02735707, NCT04505774, NCT04359277, and NCT04372589.).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1056/NEJMoa2103417DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8362592PMC
August 2021

Therapeutic Anticoagulation with Heparin in Noncritically Ill Patients with Covid-19.

N Engl J Med 2021 Aug 4;385(9):790-802. Epub 2021 Aug 4.

From the Peter Munk Cardiac Centre at University Health Network (P.R.L., M.E.F., V.D., J.P.G., L.C.G., G.H.), the University of Toronto (P.R.L., E.C.G., A.S.S., M.E.F., V.D., R.A.F., L.C.G., G.H., M.H.), University Health Network (E.C.G., M.H.), St. Michael's Hospital Unity Health (A.S.S., Z.B., J.C.M., M.S.), Ozmosis Research (L.B., L.P.G.D., V.W.), and Sunnybrook Health Sciences Centre (J.P.G.), Toronto, Ottawa Hospital Research Institute (M. Carrier, L.A.C., D.A.F., G.L.G., D.M.S.), Institut du Savoir Montfort (Marc Carrier, G.L.G.), and the University of Ottawa (L.A.C., D.A.F., D.M.S.), Ottawa, Université Laval (A.F.T.) and CHU de Québec-Université Laval Research Center (A.F.T.), Quebec, QC, the University of Manitoba (B.L.H., A. Kumar, R.Z., S.A.L., D.S., G.V.-G.), CancerCare Manitoba (B.L.H., R.Z.), and St. Boniface Hospital (N.M.), Winnipeg, MB, McGill University, Montreal (S.R.K., E.G.M.), McMaster University (P.L.G.) and the Thrombosis and Atherosclerosis Research Institute (P.L.G.), Hamilton, ON, Université de Sherbrooke, Sherbrooke, QC (F.L.), the University of British Columbia, Vancouver (S. Murthy, K.R.), and the University of Alberta, Edmonton (S.D.) - all in Canada; NYU Grossman School of Medicine (J.S.B., H.R.R., J.S.H., T.C., N.M.K., S.P.), the Icahn School of Medicine at Mount Sinai and Mount Sinai Heart (R.S.R.), NYU Langone Health, NYU Langone Hospital (T.C., J.M.H., E.Y.), and Bellevue Hospital (N.M.K.), New York, Montefiore Medical Center (M.N.G., H.H.B., S.C., J.T.C., R.N.) and Albert Einstein College of Medicine (M.N.G., H.H.B., B.T.G., A. Hope), Bronx, and NYU Langone Long Island, Mineola (R.D.H., A. Hindenburg) - all in New York; the University of Pittsburgh (M.D.N., B.J.M., D.T.H., M.M.B., D.C.A., A.J.K., C.M.L., K.L., S.K.M., C.W.S.), UPMC (M.D.N., B.J.M., D.C.A., K.L., S.K.M.), the Clinical Research, Investigation, and Systems Modeling of Acute Illness (CRISMA) Center, University of Pittsburgh (T.D.G.), and UPMC Children's Hospital of Pittsburgh (C. Horvat), Pittsburgh, and Emergency Medicine, Penn State Hershey Medical Center, Hershey (S.C.M.) - all in Pennsylvania; Instituto do Coracao, Hospital das Clinicas, Faculdade de Medicina, Universidade de Sao Paulo (J.C.N., L.C.G., F.G.L.), Avanti Pesquisa Clínica (A.S.M.), Hospital de Julho (F.O.S.), and Hospital do Coracao (F.G.Z.), Sao Paulo, Hospital do Coração de Mato Grosso do Sul and the Federal University of Mato Grosso do Sul (M.P.), Hospital Universitário Maria Aparecida Pedrossia (D.G.S.J.), and Hospital Unimed Campo Grande (D.G.S.J.), Campo Grande, and INGOH, Clinical Research Center, Goiânia (M.O.S.) - all in Brazil; Instituto Mexicano del Seguro Social, Mexico City (J.E., Y.S.P.G.); the University of Bristol and University Hospitals Bristol and Weston NHS Foundation Trust (C.A.B.), Bristol, Imperial College London (A.C.G., F.A.-B., M.A.L.), Imperial College Healthcare NHS Trust, St. Mary's Hospital (A.C.G.), the London School of Hygiene and Tropical Medicine (B.-A.K.), University College London Hospital (R.H.), Kings Healthcare Partners (B.J.H.), the Intensive Care National Audit and Research Centre (P.R.M.), Guy's and St. Thomas' NHS Foundation Trust (M.S.-H.), and King's College London (M.S.-H.), London, Oxford University (A. Beane, S.J.S.) and NHS Blood and Transplant (L.J.E., S.J.S.), Oxford, and Queen's University Belfast and Royal Victoria Hospital, Belfast (D.F.M.) - all in the United Kingdom; Zuckerberg San Francisco General Hospital, University of California, San Francisco (L.Z.K., C. Hendrickson, M.M.K., A.E.K., M.A.M., B.N.-G.), Harbor-UCLA Medical Center, Torrance (R.J.L., S. Brouwer), Global Coalition for Adaptive Research (M. Buxton) and the University of California Los Angeles (G.L.), Los Angeles, the University of California San Diego School of Medicine, San Diego (T.W.C.), and Stanford University School of Medicine, Palo Alto (J.G.W.) - all in California; Larner College of Medicine at the University of Vermont, Burlington (M. Cushman); Australian and New Zealand Intensive Care Research Centre, Monash University (Z.M., A.M.H., C.J.M., S.A.W., A. Buzgau, C.G., S.P.M., A.D.N., J.C.P., A.C.C.), and Alfred Health (A.C.C., A.D.N.), Melbourne, VIC, St. John of God Subiaco Hospital (S.A.W., E. Litton) and Fiona Stanley Hospital (E. Litton), Perth, WA, and Flinders University, Bedford Park, SA (S. Bihari) - all in Australia; the University of Illinois (K.S.K., J.R.J., J.G.Q.), Cook County Health and Rush Medical College (S. Malhotra), and the University of Chicago (J.D.P.) - all in Chicago; SOCAR Research SA, Nyon (B.-A.K.), and Inselspital, Bern University Hospital, University of Bern (T.T.), Bern - all in Switzerland; Berry Consultants, Austin (R.J.L., E. Lorenzi, S.M.B., L.R.B., M.A.D., M.F., A.M., C.T.S.), University of Texas Southwestern Medical Center, Dallas (A.P.), and Baylor Scott and White Health, Temple (R.J.W.) - all in Texas; Auckland City Hospital (C.J.M., S.P.M., R.L.P.) and the University of Auckland (R.L.P.), Auckland, and the Medical Research Institute of New Zealand, Wellington (C.J.M., A.M.T.) - all in New Zealand; Vanderbilt University Medical Center (A.W.A.) and TriStar Centennial Medical Center (A.L.G.) - both in Nashville; Fédération Hospitalo Universitaire, Raymond Poincaré Hospital, Université de Versailles Saint-Quentin-en-Yvelines, Garches (D. Annane), and Aix-Marseille University, Marseille (B.C.) - both in France; King Saud bin Abdulaziz University for Health Sciences and King Abdullah International Medical Research Center, Riyadh, Saudi Arabia (Y.M.A.); Nepal Mediciti Hospital, Lalitpur, and Nepal Intensive Care Research Foundation, Kathmandu (D. Aryal) - both in Nepal; Versiti Blood Research Institute, Milwaukee (L.B.K., L.J.E.), and the University of Wisconsin School of Medicine and Public Health, Madison (J.P.S.); National Intensive Care Surveillance-Mahidol Oxford Tropical Medicine Research Unit, Colombo, Sri Lanka (A. Beane); the University Medical Center Utrecht, Utrecht University, Utrecht (M. Bonten, R.E.G.S., W.B.-P.), and Radboud University Medical Center, Nijmegen (S. Middeldorp, F.L.V.) - both in the Netherlands; Jena University Hospital, Jena, Germany (F.B.); Cleveland Clinic (A.D.) and Case Western Reserve University, the Metro Health Medical Centre (V.K.) - both in Cleveland; Ochsner Medical Center, University of Queensland-Ochsner Clinical School, New Orleans (M.B.E.); Harvard Medical School (B.M.E., Y.K., N.S.R., A.B.S), Brigham and Women's Hospital (B.M.E., Y.K., S.M.H.), Boston University School of Medicine and Boston Medical Center (N.M.H.), and Massachusetts General Hospital (A.B.S., N.S.R.) - all in Boston; University of Alabama, Birmingham (S.G.); Hospital Ramón y Cajal (S.G.-M., J.L.L.-S.M., R.M.G.) and IdiPaz Research Institute, Universidad Autonoma (J.L.-S.), Madrid, and University Hospital of Salamanca-University of Salamanca-IBSAL, Salamanca (M.M.) - all in Spain; University of Antwerp, Wilrijk, Belgium (H.G.); Rutgers New Jersey Medical School, Newark (Y.Y.G.); University of Oxford, Bangkok, Thailand (R.H.); Ascension St. John Heart and Vascular Center, Tulsa (N.H.), and the University of Oklahoma College of Medicine, Oklahoma City (N.H.); the University of Cincinnati, Cincinnati (K.H.); University of Michigan, Ann Arbor (R.C.H., P.K.P.), Beaumont Health, Royal Oak, and the OUWB School of Medicine, Auburn Hills (G.B.N.) - all in Michigan; Mayo Clinic, Rochester (V.N.I.), and the Hennepin County Medical Center, Minneapolis (M.E.P.) - both in Minnesota; Apollo Speciality Hospital-OMR, Chennai, India (D.J.); Oregon Health and Science University, Portland (A. Khan, E.S.L.); the National Heart, Lung, and Blood Institute, Bethesda, MD (A.L.K.); University of Mississippi Medical Center, Jackson (M.E.K.); University College Dublin, Dublin (A.D.N.); University of Kansas School of Medicine, Kansas City (L.S.); Duke University Hospital, Durham, NC (L.W.); and Emory University, Atlanta (B.J.W.).

Background: Thrombosis and inflammation may contribute to the risk of death and complications among patients with coronavirus disease 2019 (Covid-19). We hypothesized that therapeutic-dose anticoagulation may improve outcomes in noncritically ill patients who are hospitalized with Covid-19.

Methods: In this open-label, adaptive, multiplatform, controlled trial, we randomly assigned patients who were hospitalized with Covid-19 and who were not critically ill (which was defined as an absence of critical care-level organ support at enrollment) to receive pragmatically defined regimens of either therapeutic-dose anticoagulation with heparin or usual-care pharmacologic thromboprophylaxis. The primary outcome was organ support-free days, evaluated on an ordinal scale that combined in-hospital death (assigned a value of -1) and the number of days free of cardiovascular or respiratory organ support up to day 21 among patients who survived to hospital discharge. This outcome was evaluated with the use of a Bayesian statistical model for all patients and according to the baseline d-dimer level.

Results: The trial was stopped when prespecified criteria for the superiority of therapeutic-dose anticoagulation were met. Among 2219 patients in the final analysis, the probability that therapeutic-dose anticoagulation increased organ support-free days as compared with usual-care thromboprophylaxis was 98.6% (adjusted odds ratio, 1.27; 95% credible interval, 1.03 to 1.58). The adjusted absolute between-group difference in survival until hospital discharge without organ support favoring therapeutic-dose anticoagulation was 4.0 percentage points (95% credible interval, 0.5 to 7.2). The final probability of the superiority of therapeutic-dose anticoagulation over usual-care thromboprophylaxis was 97.3% in the high d-dimer cohort, 92.9% in the low d-dimer cohort, and 97.3% in the unknown d-dimer cohort. Major bleeding occurred in 1.9% of the patients receiving therapeutic-dose anticoagulation and in 0.9% of those receiving thromboprophylaxis.

Conclusions: In noncritically ill patients with Covid-19, an initial strategy of therapeutic-dose anticoagulation with heparin increased the probability of survival to hospital discharge with reduced use of cardiovascular or respiratory organ support as compared with usual-care thromboprophylaxis. (ATTACC, ACTIV-4a, and REMAP-CAP ClinicalTrials.gov numbers, NCT04372589, NCT04505774, NCT04359277, and NCT02735707.).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1056/NEJMoa2105911DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8362594PMC
August 2021

'Drip-and-ship' intravenous thrombolysis and outcomes for large vessel occlusion thrombectomy candidates in a hub-and-spoke telestroke model.

J Neurointerv Surg 2021 Jul 29. Epub 2021 Jul 29.

Neurosurgery, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA.

Background: Randomized trials have not demonstrated benefit from intravenous thrombolysis among patients undergoing endovascular thrombectomy (EVT). However, these trials included primarily patients presenting directly to an EVT capable hub center. We sought to study outcomes for EVT candidates who presented to spoke hospitals and were subsequently transferred for EVT consideration, comparing those administered alteplase at spokes (i.e., 'drip-and-ship' model) versus those not.

Methods: Consecutive EVT candidates presenting to 25 spokes from 2018 to 2020 with pre-transfer CT angiography defined emergent large vessel occlusion and Alberta Stroke Program CT score ≥6 were identified from a prospectively maintained Telestroke database. Outcomes of interest included adequate reperfusion (Thrombolysis in Cerebral Infarction (TICI) 2b-3), intracerebral hemorrhage (ICH), discharge functional independence (modified Rankin Scale (mRS) ≤2), and 90 day functional independence.

Results: Among 258 patients, median age was 70 years (IQR 60-81), median National Institutes of Health Stroke Scale (NIHSS) score was 13 (6-19), and 50% were women. Ninety-eight (38%) were treated with alteplase at spokes and 113 (44%) underwent EVT at the hub. Spoke alteplase use independently increased the odds of discharge mRS ≤2 (adjusted OR 2.43, 95% CI 1.08 to 5.46, p=0.03) and 90 day mRS ≤2 (adjusted OR 3.45, 95% CI 1.65 to 7.22, p=0.001), even when controlling for last known well, NIHSS, and EVT; it was not associated with an increased risk of ICH (OR 1.04, 95% CI 0.39 to 2.78, p=0.94), and there was a trend toward association with greater TICI 2b-3 (OR 3.59, 95% CI 0.94 to 13.70, p=0.06).

Conclusions: Intravenous alteplase at spoke hospitals may improve discharge and 90 day mRS and should not be withheld from EVT eligible patients who first present at alteplase capable spoke hospitals that do not perform EVT. Additional studies are warranted to confirm and further explore these benefits.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1136/neurintsurg-2021-017819DOI Listing
July 2021

MRI Radiomic Signature of White Matter Hyperintensities Is Associated With Clinical Phenotypes.

Front Neurosci 2021 12;15:691244. Epub 2021 Jul 12.

Department of Neurology, Washington University School of Medicine and Barnes-Jewish Hospital, St. Louis, MO, United States.

Objective: Neuroimaging measurements of brain structural integrity are thought to be surrogates for brain health, but precise assessments require dedicated advanced image acquisitions. By means of quantitatively describing conventional images, radiomic analyses hold potential for evaluating brain health. We sought to: (1) evaluate radiomics to assess brain structural integrity by predicting white matter hyperintensities burdens (WMH) and (2) uncover associations between predictive radiomic features and clinical phenotypes.

Methods: We analyzed a multi-site cohort of 4,163 acute ischemic strokes (AIS) patients with T2-FLAIR MR images with total brain and WMH segmentations. Radiomic features were extracted from normal-appearing brain tissue (brain mask-WMH mask). Radiomics-based prediction of personalized WMH burden was done using ElasticNet linear regression. We built a radiomic signature of WMH with stable selected features predictive of WMH burden and then related this signature to clinical variables using canonical correlation analysis (CCA).

Results: Radiomic features were predictive of WMH burden ( = 0.855 ± 0.011). Seven pairs of canonical variates (CV) significantly correlated the radiomics signature of WMH and clinical traits with respective canonical correlations of 0.81, 0.65, 0.42, 0.24, 0.20, 0.15, and 0.15 (FDR-corrected -values < 0.001, -value = 0.012). The clinical CV1 was mainly influenced by age, CV2 by sex, CV3 by history of smoking and diabetes, CV4 by hypertension, CV5 by atrial fibrillation (AF) and diabetes, CV6 by coronary artery disease (CAD), and CV7 by CAD and diabetes.

Conclusion: Radiomics extracted from T2-FLAIR images of AIS patients capture microstructural damage of the cerebral parenchyma and correlate with clinical phenotypes, suggesting different radiographical textural abnormalities per cardiovascular risk profile. Further research could evaluate radiomics to predict the progression of WMH and for the follow-up of stroke patients' brain health.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fnins.2021.691244DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8312571PMC
July 2021

Generative lesion pattern decomposition of cognitive impairment after stroke.

Brain Commun 2021 22;3(2):fcab110. Epub 2021 May 22.

Department of Biomedical Engineering, McConnell Brain Imaging Centre, Montreal Neurological Institute, Faculty of Medicine, School of Computer Science, McGill University, Montreal, Canada.

Cognitive impairment is a frequent and disabling sequela of stroke. There is however incomplete understanding of how lesion topographies in the left and right cerebral hemisphere brain interact to cause distinct cognitive deficits. We integrated machine learning and Bayesian hierarchical modelling to enable a hemisphere-aware analysis of 1080 acute ischaemic stroke patients with deep profiling ∼3 months after stroke. We show the relevance of the left hemisphere in the prediction of language and memory assessments and relevance of the right hemisphere in the prediction of visuospatial functioning. Global cognitive impairments were equally well predicted by lesion topographies from both sides. Damage to the hippocampal and occipital regions on the left was particularly informative about lost naming and memory functions, while damage to these regions on the right was linked to lost visuospatial functioning. Global cognitive impairment was predominantly linked to lesioned tissue in the supramarginal and angular gyrus, the post-central gyrus as well as the lateral occipital and opercular cortices of the left hemisphere. Hence, our analysis strategy uncovered that lesion patterns with unique hemispheric distributions are characteristic of how cognitive capacity is lost due to ischaemic brain tissue damage.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/braincomms/fcab110DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8233115PMC
May 2021

Outcome after acute ischemic stroke is linked to sex-specific lesion patterns.

Nat Commun 2021 06 2;12(1):3289. Epub 2021 Jun 2.

Department of Neurology, Washington University School of Medicine & Barnes-Jewish Hospital, St Louis, MO, USA.

Acute ischemic stroke affects men and women differently. In particular, women are often reported to experience higher acute stroke severity than men. We derived a low-dimensional representation of anatomical stroke lesions and designed a Bayesian hierarchical modeling framework tailored to estimate possible sex differences in lesion patterns linked to acute stroke severity (National Institute of Health Stroke Scale). This framework was developed in 555 patients (38% female). Findings were validated in an independent cohort (n = 503, 41% female). Here, we show brain lesions in regions subserving motor and language functions help explain stroke severity in both men and women, however more widespread lesion patterns are relevant in female patients. Higher stroke severity in women, but not men, is associated with left hemisphere lesions in the vicinity of the posterior circulation. Our results suggest there are sex-specific functional cerebral asymmetries that may be important for future investigations of sex-stratified approaches to management of acute ischemic stroke.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41467-021-23492-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8172535PMC
June 2021

Sex-specific differences in presentations and determinants of outcomes after endovascular thrombectomy for large vessel occlusion stroke.

J Neurol 2021 May 29. Epub 2021 May 29.

Neurology, Massachusetts General Hospital, 55 Fruit St, WAC-7-721, Boston, MA, USA.

Introduction: Sex-specific differences in ischemic stroke outcomes are prevalent. We sought to investigate sex differences in the determinants of reperfusion and functional outcomes after endovascular thrombectomy (EVT) for emergent large vessel occlusion ischemic stroke (ELVO).

Methods: Patients presenting to a single referral center with an anterior circulation ELVO that underwent EVT from 2011 to 2019 were included in this retrospective analysis. Sex differences in history, presentation, adequate reperfusion (TICI 2b-3), and 90-day good outcome [delta modified Rankin Scale (mRS) ≤ 2 from pre-stroke] were examined. Multivariable logistic regression analyses were performed to assess sex-specific associations with outcomes.

Results: Three hundred and eighty-one consecutive ELVO patients were identified. Women (N = 193) were older (75 vs 64 years, p < 0.0001), had more pre-stroke disability (17% vs 9%, p = 0.032), more atrial fibrillation (41% vs 30%, p = 0.033), but less carotid atherosclerosis (8% vs 16%, p = 0.027). Rates of TICI 2b-3 and good outcome were similar between sexes. Carotid atherosclerosis (OR 0.315, 95% CI 0.130, 0.762) and dissection (OR 0.124, 95% CI 0.027, 0.569) independently decreased the odds of TICI 2b-3 among men but not women. Older age, more severe stroke, and not achieving TICI 2b-3 independently decreased the odds of good outcome among both sexes, while prior stroke (OR 0.258, 95% CI 0.083, 0.797) and hemorrhagic transformation (OR 0.111, 0.021, 0.592) were determinants exclusive to men.

Conclusion: In a real-world analysis of ELVO stroke patients treated with EVT, we found that despite advanced age and more pre-stroke disability, women have comparable reperfusion rates and functional outcomes compared to men. Sex-specific determinants of reperfusion and functional outcome were identified that require further study.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00415-021-10628-0DOI Listing
May 2021

Cognitive Impairment and Dementia After Stroke: Design and Rationale for the DISCOVERY Study.

Stroke 2021 Aug 27;52(8):e499-e516. Epub 2021 May 27.

J. Philip Kistler Stroke Research Center, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston (N.S.R., S.M.G.).

Stroke is a leading cause of the adult disability epidemic in the United States, with a major contribution from poststroke cognitive impairment and dementia (PSCID), the rates of which are disproportionally high among the health disparity populations. Despite the PSCID's overwhelming impact on public health, a knowledge gap exists with regard to the complex interaction between the acute stroke event and highly prevalent preexisting brain pathology related to cerebrovascular and Alzheimer disease or related dementia. Understanding the factors that modulate PSCID risk in relation to index stroke event is critically important for developing personalized prognostication of PSCID, targeted interventions to prevent it, and for informing future clinical trial design. The DISCOVERY study (Determinants of Incident Stroke Cognitive Outcomes and Vascular Effects on Recovery), a collaborative network of thirty clinical performance clinical sites with access to acute stroke populations and the expertise and capacity for systematic assessment of PSCID will address this critical challenge. DISCOVERY is a prospective, multicenter, observational, nested-cohort study of 8000 nondemented ischemic and hemorrhagic stroke patients enrolled at the time of index stroke and followed for a minimum of 2 years, with serial cognitive evaluations and assessments of functional outcome, with subsets undergoing research magnetic resonance imaging and positron emission tomography and comprehensive genetic/genomic and fluid biomarker testing. The overall scientific objective of this study is to elucidate mechanisms of brain resilience and susceptibility to PSCID in diverse US populations based on complex interplay between life-course exposure to multiple vascular risk factors, preexisting burden of microvascular and neurodegenerative pathology, the effect of strategic acute stroke lesions, and the mediating effect of genomic and epigenomic variation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1161/STROKEAHA.120.031611DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8316324PMC
August 2021

White Matter Hyperintensity and Cardiovascular Disease Outcomes in the SPRINT MIND Trial.

J Stroke Cerebrovasc Dis 2021 Jun 3;30(6):105764. Epub 2021 Apr 3.

Departments of Neurology: University of Utah, MUSC, Johns Hopkins University, University of Chicago, MGH, 175 N. Medical Dr, Salt Lake City, UT 84132, USA. Electronic address:

Background: The Systolic Blood Pressure Intervention Trial (SPRINT) randomized patients to a goal systolic blood pressure (SBP) <120 mm Hg vs. <140 mm Hg. In a subset of participants, the SPRINT MIND ancillary study performed a baseline MRI and measured white matter hyperintensity volume (WMHv). In this secondary analysis, we evaluated the association between baseline WMHv and cardiovascular events during follow-up in the overall sample.

Methods: The primary outcome was the same as SPRINT, a composite of stroke, myocardial infarction, acute coronary syndrome, decompensated congestive heart failure, or cardiovascular death. We fit Cox models to the primary outcome and report adjusted hazard ratios (HR) for log-transformed WMHv and quartiles of WMHv.

Results: Among 717 participants, the median (IQR) baseline WMHv was 1.62 (0.66-3.98) mL. The primary outcome occurred in 51/719 (7.1%). The median WMHv was higher in patients with the primary outcome (3.40 mL versus 1.56 mL, p < 0.001). In adjusted models, WMHv as a log-transformed continuous variable was associated with the primary outcome (HR 1.44, 95% CI 1.15-1.80). The highest quartile of WMHv, compared to the lowest, was also independently associated with the primary outcome (HR 3.21, 95% CI 1.27-8.13).

Conclusions: We found that the baseline volume of WMH was associated with future CVD risk in SPRINT MIND. Prospective clinical trials with larger sample sizes than the current study are needed to determine whether intensive BP lowering can reduce the high cardiovascular risk in patients with WMH.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jstrokecerebrovasdis.2021.105764DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8107132PMC
June 2021

International stroke genetics consortium recommendations for studies of genetics of stroke outcome and recovery.

Int J Stroke 2021 Apr 26:17474930211007288. Epub 2021 Apr 26.

Stroke Pharmacogenomics and Genetics Group, Sant Pau Biomedical Research Institute, Barcelona, Spain.

Numerous biological mechanisms contribute to outcome after stroke, including brain injury, inflammation, and repair mechanisms. Clinical genetic studies have the potential to discover biological mechanisms affecting stroke recovery in humans and identify intervention targets. Large sample sizes are needed to detect commonly occurring genetic variations related to stroke brain injury and recovery. However, this usually requires combining data from multiple studies where consistent terminology, methodology, and data collection timelines are essential. Our group of expert stroke and rehabilitation clinicians and researchers with knowledge in genetics of stroke recovery here present recommendations for harmonizing phenotype data with focus on measures suitable for multicenter genetic studies of ischemic stroke brain injury and recovery. Our recommendations have been endorsed by the International Stroke Genetics Consortium.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/17474930211007288DOI Listing
April 2021

Abnormal dynamic functional connectivity is linked to recovery after acute ischemic stroke.

Hum Brain Mapp 2021 May 2;42(7):2278-2291. Epub 2021 Mar 2.

J. Philip Kistler Stroke Research Center, Massachusetts General Hospital, Boston, Massachusetts, USA.

The aim of the current study was to explore the whole-brain dynamic functional connectivity patterns in acute ischemic stroke (AIS) patients and their relation to short and long-term stroke severity. We investigated resting-state functional MRI-based dynamic functional connectivity of 41 AIS patients two to five days after symptom onset. Re-occurring dynamic connectivity configurations were obtained using a sliding window approach and k-means clustering. We evaluated differences in dynamic patterns between three NIHSS-stroke severity defined groups (mildly, moderately, and severely affected patients). Furthermore, we built Bayesian hierarchical models to evaluate the predictive capacity of dynamic connectivity and examine the interrelation with clinical measures, such as white matter hyperintensity lesions. Finally, we established correlation analyses between dynamic connectivity and AIS severity as well as 90-day neurological recovery (ΔNIHSS). We identified three distinct dynamic connectivity configurations acutely post-stroke. More severely affected patients spent significantly more time in a configuration that was characterized by particularly strong connectivity and isolated processing of functional brain domains (three-level ANOVA: p < .05, post hoc t tests: p < .05, FDR-corrected). Configuration-specific time estimates possessed predictive capacity of stroke severity in addition to the one of clinical measures. Recovery, as indexed by the realized change of the NIHSS over time, was significantly linked to the dynamic connectivity between bilateral intraparietal lobule and left angular gyrus (Pearson's r = -.68, p = .003, FDR-corrected). Our findings demonstrate transiently increased isolated information processing in multiple functional domains in case of severe AIS. Dynamic connectivity involving default mode network components significantly correlated with recovery in the first 3 months poststroke.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/hbm.25366DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8046120PMC
May 2021

Spatial-Intensity Transform GANs for High Fidelity Medical Image-to-Image Translation.

Med Image Comput Comput Assist Interv 2020 Oct 29;12262:749-759. Epub 2020 Sep 29.

Computer Science and Artificial Intelligence Lab, MIT, Cambridge, MA, USA.

Despite recent progress in image-to-image translation, it remains challenging to apply such techniques to clinical quality medical images. We develop a novel parameterization of conditional generative adversarial networks that achieves high image fidelity when trained to transform MRIs conditioned on a patient's age and disease severity. The spatial-intensity transform generative adversarial network (SIT-GAN) constrains the generator to a smooth spatial transform composed with sparse intensity changes. This technique improves image quality and robustness to artifacts, and generalizes to different scanners. We demonstrate SIT-GAN on a large clinical image dataset of stroke patients, where it captures associations between ventricle expansion and aging, as well as between white matter hyperintensities and stroke severity. Additionally, SIT-GAN provides a disentangled view of the variation in shape and appearance across subjects.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/978-3-030-59713-9_72DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7888153PMC
October 2020

Intracranial hemorrhage in patients with atrial fibrillation receiving anticoagulation with warfarin or edoxaban: An in-depth analysis from the ENGAGE AF-TIMI 48 randomized trial.

J Clin Neurosci 2021 Apr 12;86:294-300. Epub 2021 Jan 12.

TIMI Study Group, Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA. Electronic address:

Intracranial hemorrhage (ICH) is a known risk of oral anticoagulation; delineating ICH attributes may provide nuanced guidance regarding atrial fibrillation management. We evaluated ICH characteristics and outcomes from Effective Anticoagulation with Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction 48 (ENGAGE AF-TIMI 48), a randomized trial that compared two edoxaban regimens (higher-dose edoxaban regimen 60/30 mg (HDER), lower-dose edoxaban regimen 30/15 mg (LDER)) with warfarin in patients with atrial fibrillation. Patients who suffered ICH vs those who did not were compared and independent predictors of ICH were calculated. We also assessed ICH subtype and etiology. Of 21,105 randomized patients, 322 (1.53%) had ≥ 1 ICH for a total of 368 events. Intraparenchymal hemorrhage (HDER: HR 0.52 [95% CI 0.35-0.77], LDER: HR 0.22 [0.13-0.38]) and subdural hematoma (HDER: HR 0.29 [0.15-0.55], LDER: HR 0.26 [0.13-0.50]) were lower with both HDER and LDER vs warfarin. Subarachnoid hemorrhage frequency was similar in the HDER vs warfarin groups but lower in LDER. Compared to warfarin, edoxaban was associated with lower risk of spontaneous ICH (HDER: HR 0.47 [0.31-0.69], LDER: HR 0.34 [0.22-0.53]) and traumatic ICH (HDER: HR 0.32 [0.17-0.61], LDER: HR 0.31 [0.16-0.59]). In multivariable analysis, randomization to warfarin, increased age, and risk of falling remained independent predictors of ICH. In ENGAGE AF-TIMI 48, ICH was decreased in edoxaban-treated patients compared to warfarin-treated patients, including ICH of both spontaneous and traumatic causes. Both edoxaban regimens lowered intraparenchymal and subdural hemorrhages compared to warfarin. Patient characteristics and medical history may help guide anticoagulation management.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jocn.2020.10.036DOI Listing
April 2021

White Matter Acute Infarct Volume After Thrombectomy for Anterior Circulation Large Vessel Occlusion Stroke is Associated with Long Term Outcomes.

J Stroke Cerebrovasc Dis 2021 Mar 29;30(3):105567. Epub 2020 Dec 29.

Department of Neurology, Massachusetts General Hospital, Harvard Medical School, USA.

Objectives: Despite the proven efficacy of endovascular thrombectomy (EVT) for large vessel occlusion stroke, over half treated remain functionally disabled or die. Infarct topography may have implications for prognostication, patient selection, and the development of tissue-specific neuroprotective agents. We sought to quantify white matter injury in anterior circulation acute infarcts post-EVT to understand its significance and identify its determinants.

Materials And Methods: Demographics, history, presentations, and outcomes for consecutive patients treated with EVT were recorded in a prospectively maintained database at a single center. Acute infarct masks were coregistered to standard space. Standard atlases of white matter, cortex, and basal ganglia were used to determine region-specific infarct volumes.

Results: 167 individuals were identified with median age 69 years and 53% women. 85% achieved adequate reperfusion (TICI 2b-3) after EVT; 43% achieved 90-day functional independence (mRS 0-2). Median infarct volumes were 45cc (IQR 18-122) for total, 17cc (6-49) for white matter, 21cc (4-53) for cortex, and 5cc (1-8) for basal ganglia. The odds of 90-day mRS 0-2 were reduced in patients with larger white matter infarct volume (cc, OR=0.89, 95%CI=0.81-0.96), independent of cortex infarct volume, basal ganglia infarct volume, age, NIHSS, and TICI 2b-3 reperfusion. Reperfusion-to-MRI time was associated with white matter infarct volume (hr, β=0.119, p=0.017), but not cortical or basal ganglia infarct volume.

Conclusions: These data quantitatively describe region-specific infarct volumes after EVT and suggest the clinical relevance of white matter infarct volume as a predictor of long-term outcomes. Further study is warranted to examine delayed white matter infarction and the significance of specific white matter tracts.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jstrokecerebrovasdis.2020.105567DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7880897PMC
March 2021

Automated Electronic Phenotyping of Cardioembolic Stroke.

Stroke 2021 01 10;52(1):181-189. Epub 2020 Dec 10.

Cardiovascular Research Center and Cardiac Arrhythmia Service (W.G., S.K., A.T.T.L., L.X.H., S.A.L.), Massachusetts General Hospital, Boston.

Background And Purpose: Oral anticoagulation is generally indicated for cardioembolic strokes, but not for other stroke causes. Consequently, subtype classification of ischemic stroke is important for risk stratification and secondary prevention. Because manual classification of ischemic stroke is time-intensive, we assessed the accuracy of automated algorithms for performing cardioembolic stroke subtyping using an electronic health record (EHR) database.

Methods: We adapted TOAST (Trial of ORG 10172 in Acute Stroke Treatment) features associated with cardioembolic stroke for derivation in the EHR. Using administrative codes and echocardiographic reports within Mass General Brigham Biobank (N=13 079), we iteratively developed EHR-based algorithms to define the TOAST cardioembolic stroke features, revising regular expression algorithms until achieving positive predictive value ≥80%. We compared several machine learning-based statistical algorithms for discriminating cardioembolic stroke using the feature algorithms applied to EHR data from 1598 patients with acute ischemic strokes from the Massachusetts General Hospital Ischemic Stroke Registry (2002-2010) with previously adjudicated TOAST and Causative Classification of Stroke subtypes.

Results: Regular expression-based feature extraction algorithms achieved a mean positive predictive value of 95% (range, 88%-100%) across 11 echocardiographic features. Among 1598 patients from the Massachusetts General Hospital Ischemic Stroke Registry, 1068 had any cardioembolic stroke feature within predefined time windows in proximity to the stroke event. Cardioembolic stroke tended to occur at an older age, with more TOAST-based comorbidities, and with atrial fibrillation (82.3%). The best model was a random forest with 92.2% accuracy and area under the receiver operating characteristic curve of 91.1% (95% CI, 87.5%-93.9%). Atrial fibrillation, age, dilated cardiomyopathy, congestive heart failure, patent foramen ovale, mitral annulus calcification, and recent myocardial infarction were the most discriminatory features.

Conclusions: Machine learning-based identification of cardioembolic stroke using EHR data is feasible. Future work is needed to improve the accuracy of automated cardioembolic stroke identification and assess generalizability of electronic phenotyping algorithms across clinical settings.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1161/STROKEAHA.120.030663DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7769922PMC
January 2021

White Matter Hyperintensity Burden Is Associated With Hippocampal Subfield Volume in Stroke.

Front Neurol 2020 26;11:588883. Epub 2020 Oct 26.

Department of Neurology, J. Philip Kistler Stroke Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States.

White matter hyperintensities of presumed vascular origin (WMH) are a prevalent form of cerebral small-vessel disease and an important risk factor for post-stroke cognitive dysfunction. Despite this prevalence, it is not well understood how WMH contributes to post-stroke cognitive dysfunction. Preliminary findings suggest that increasing WMH volume is associated with total hippocampal volume in chronic stroke patients. The hippocampus, however, is a complex structure with distinct subfields that have varying roles in the function of the hippocampal circuitry and unique anatomical projections to different brain regions. For these reasons, an investigation into the relationship between WMH and hippocampal subfield volume may further delineate how WMH predispose to post-stroke cognitive dysfunction. In a prospective study of acute ischemic stroke patients with moderate/severe WMH burden, we assessed the relationship between quantitative WMH burden and hippocampal subfield volumes. Patients underwent a 3T MRI brain within 2-5 days of stroke onset. Total WMH volume was calculated in a semi-automated manner. Mean cortical thickness and hippocampal volumes were measured in the contralesional hemisphere. Total and subfield hippocampal volumes were measured using an automated, high-resolution, computational atlas. Linear regression analyses were performed for predictors of total and subfield hippocampal volumes. Forty patients with acute ischemic stroke and moderate/severe white matter hyperintensity burden were included in this analysis. Median WMH volume was 9.0 cm. Adjusting for intracranial volume and stroke laterality, age (β = -3.7, < 0.001), hypertension (β = -44.7, = 0.04), WMH volume (β = -0.89, = 0.049), and mean cortical thickness (β = 286.2, = 0.006) were associated with total hippocampal volume. In multivariable analysis, age (β = -3.3, < 0.001) and cortical thickness (β = 205.2, = 0.028) remained independently associated with total hippocampal volume. In linear regression for predictors of hippocampal subfield volume, increasing WMH volume was associated with decreased hippocampal-amygdala transition area volume (β = -0.04, = 0.001). These finding suggest that in ischemic stroke patients, increased WMH burden is associated with selective hippocampal subfield degeneration in the hippocampal-amygdala transition area.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fneur.2020.588883DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7649326PMC
October 2020

Toward a more inclusive paradigm: thrombectomy for stroke patients with pre-existing disabilities.

J Neurointerv Surg 2021 Oct 30;13(10):865-868. Epub 2020 Oct 30.

Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA.

Background: Persons with pre-existing disabilities represent over one-third of acute stroke presentations, but account for a far smaller proportion of those receiving endovascular thrombectomy (EVT) and thrombolysis. This is despite existing ethical, economic, legal, and social directives to maximize equity for this vulnerable population. We sought to determine associations between baseline modified Rankin Scale (mRS) and outcomes after EVT.

Methods: Individuals who underwent EVT were identified from a prospectively maintained database. Demographics, medical history, presentations, treatments, and outcomes were recorded. Baseline disability was defined as baseline mRS≥2. Accumulated disability was defined as the delta between baseline mRS and absolute 90-day mRS.

Results: Of 381 individuals, 49 had baseline disability (five with mRS=4, 23 mRS=3, 21 mRS=2). Those with baseline disability were older (81 vs 68 years, P<0.0001), more likely female (65% vs 49%, P=0.032), had more coronary disease (39% vs 20%, P=0.006), stroke/TIA history (35% vs 15%, P=0.002), and higher NIH Stroke Scale (19 vs 16, P=0.001). Baseline mRS was associated with absolute 90-day mRS ≤2 (OR=0.509, 95%CI=0.370-0.700). However, baseline mRS bore no association with accumulated disability by delta mRS ≤0 (ie, return to baseline, OR=1.247, 95%CI=0.943-1.648), delta mRS ≤1 (OR=1.149, 95%CI=0.906-1.458), delta mRS ≤2 (OR 1.097, 95% CI 0.869-1.386), TICI 2b-3 reperfusion (OR=0.914, 95%CI=0.712-1.173), final infarct size (P=0.853, β=-0.014), or intracerebral hemorrhage (OR=0.521, 95%CI=0.244-1.112).

Conclusions: While baseline mRS was associated with absolute 90-day disability, there was no association with accumulated disability or other outcomes. Patients with baseline disability should not be routinely excluded from EVT based on baseline mRS alone.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1136/neurintsurg-2020-016783DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8365380PMC
October 2021

Infarct Growth despite Endovascular Thrombectomy Recanalization in Large Vessel Occlusive Stroke.

J Neuroimaging 2021 01 29;31(1):155-164. Epub 2020 Oct 29.

Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA.

Background And Purpose: Endovascular thrombectomy (EVT) has revolutionized large vessel occlusion stroke care. However, not all patients with good endovascular results achieve good outcomes. We sought to understand the clinical significance of magnetic resonance imaging defined infarct growth despite adequate reperfusion and identify associated clinical and radiographic variables.

Methods: History, presentation, treatments, and outcomes for consecutive EVT patients at a referral center were collected. Adequate reperfusion was defined as thrombolysis in cerebral infarction (TICI) score 2b-3. Region-specific infarct volumes in white matter, cortex, and basal ganglia were determined on diffusion-weighted imaging. Infarct growth was defined as post-EVT minus pre-EVT volume. Good outcome was defined as 90-day modified Rankin Scale ≤2.

Results: Forty-four patients with adequate reperfusion were identified with median age 72 years; 64% were women. Each region showed infarct growth: white matter (median pre-EVT 7 cubic centimeters [cc], post-EVT 16 cc), cortex (4 cc, 15 cc), basal ganglia (2 cc, 4 cc), total (20 cc, 39 cc). In multivariable regression, total infarct growth independently decreased the odds of good outcome (odds ratio = .946, 95% CI = .897, .998). Further multivariable analyses for determinants of infarct growth identified female sex was associated with less total growth (β = -.294, P = .042), TICI 3 was associated with less white matter growth (β = -.277, P = .048) and cortical growth (β = -.335, P = .017), and both female sex (β = -.332, P = .015) and coronary disease (β = -.337, P = .015) were associated with less cortical growth.

Conclusions: Infarct growth occurred despite adequate reperfusion, disproportionately in the cortex, and independently decreased the odds of good outcome. Infarct growth occurred while patients were hospitalized and may represent a therapeutic target. Potential determinants of region-specific infarct growth were identified that require confirmation in larger studies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/jon.12796DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8365346PMC
January 2021

Association of common genetic variants with brain microbleeds: A genome-wide association study.

Neurology 2020 12 10;95(24):e3331-e3343. Epub 2020 Sep 10.

From the Departments of Epidemiology (M.J.K., H.H.H.A., D.V., S.J.v.d.L., P.Y., M.W.V., N.A., C.M.v.D., M.A.I.), Radiology and Nuclear Medicine (H.H.H.A., P.Y., A.v.d.L., M.W.V.), and Clinical Genetics (H.H.H.A.), Erasmus MC University Medical Center, Rotterdam, the Netherlands; Stroke Research Group, Department of Clinical Neurosciences (D.L., M.T., J.L., D.J.T., H.S.M.), University of Cambridge, UK; Department of Neurology (J.R.J.R., C.L.S., J.J.H., A.S.B., C.D., S. Seshadri), Boston University School of Medicine; The Framingham Heart Study (J.R.J.R., C.L.S., J.J.H., A.S.B., S. Seshadri), MA; Department of Biostatistics (A.V.S.), University of Michigan, Ann Arbor; Icelandic Heart Association (A.V.S., S. Sigurdsson, V.G.), Kopavogur, Iceland; Brown Foundation Institute of Molecular Medicine, McGovern Medical School (M.F.), and Human Genetics Center, School of Public Health (M.F.), University of Texas Health Science Center at Houston; Clinical Division of Neurogeriatrics, Department of Neurology (E.H., L.P., R.S.), Institute for Medical Informatics, Statistics and Documentation (E.H.), and Gottfried Schatz Research Center, Department of Molecular Biology and Biochemistry (Y.S., H.S.), Medical University of Graz, Austria; Center of Cerebrovascular Diseases, Department of Neurology (J.L.), West China Hospital, Sichuan University, Chengdu; Stroke Research Centre, Queen Square Institute of Neurology (I.C.H., D.W., H.H., D.J.W.), University College London, UK; Department of Neurosurgery (I.C.H.), Klinikum rechts der Isar, University of Munich, Germany; Centre for Cognitive Ageing and Cognitive Epidemiology, Psychology (M.L., D.C.M.L., M.E.B., I.J.D., J.M.W.), and Centre for Clinical Brain Sciences, Edinburgh Imaging, UK Dementia Research Institute (M.E.B., J.M.W.), University of Edinburgh, UK; Department of Internal Medicine, Section of Gerontology and Geriatrics (S.T.), Department of Cardiology (S.T., J.v.d.G., J.W.J.), Section of Molecular Epidemiology, Biomedical Data Sciences (E.B.v.d.A., M.B., P.E.S.), Leiden Computational Biology Center, Biomedical Data Sciences (E.B.v.d.A.), Department of Radiology (J.v.d.G.), and Einthoven Laboratory for Experimental Vascular Medicine (J.W.J.), Leiden University Medical Center, the Netherlands; Department of Neurology (A.-K.G., N.S.R.), Massachusetts General Hospital, Harvard Medical School, Boston; Memory Aging and Cognition Center (S.H., C.C.), National University Health System, Singapore; Department of Pharmacology (S.H., C.C.) and Saw Swee Hock School of Public Health (S.H.), National University of Singapore and National University Health System, Singapore; Pattern Recognition & Bioinformatics (E.B.v.d.A.), Delft University of Technology, the Netherlands; Department of Biostatistics (S.L., J.J.H., Q.Y., A.S.B.), Boston University School of Public Health, MA; Department of Radiology (C.R.J., K.K.), Mayo Clinic, Rochester, MN; Glenn Biggs Institute for Alzheimer's & Neurodegenerative Diseases (C.L.S., S. Seshadri), UT Health San Antonio, TX; Department of Medicine, Division of Geriatrics (B.G.W., T.H.M), and Memory Impairment and Neurodegenerative Dementia (MIND) Center (T.H.M.), University of Mississippi Medical Center, Jackson; Singapore Eye Research Institute (C.Y.C., J.Y.K., T.Y.W.); Department of Neuroradiology (Z.M., J.M.W.), NHS Lothian, Edinburgh; Institute of Cardiovascular and Medical Sciences (D.J.S.), College of Medical, Veterinary and Life Sciences, University of Glasgow, UK; Division of Cerebrovascular Neurology (R.F.G.), Johns Hopkins University, Baltimore, MD; Department of Neuroradiology (A.D.M.), Atkinson Morley Neurosciences Centre, St George's NHS Foundation Trust, London, UK; Department of Neurology (C.D.), University of California at Davis; Nuffield Department of Population Health (C.M.v.D.), University of Oxford, UK; Laboratory of Epidemiology and Population Sciences (L.J.L.), National Institute on Aging, Baltimore, MD; and Faculty of Medicine (V.G.), University of Iceland, Reykjavik, Iceland.

Objective: To identify common genetic variants associated with the presence of brain microbleeds (BMBs).

Methods: We performed genome-wide association studies in 11 population-based cohort studies and 3 case-control or case-only stroke cohorts. Genotypes were imputed to the Haplotype Reference Consortium or 1000 Genomes reference panel. BMBs were rated on susceptibility-weighted or T2*-weighted gradient echo MRI sequences, and further classified as lobar or mixed (including strictly deep and infratentorial, possibly with lobar BMB). In a subset, we assessed the effects of ε2 and ε4 alleles on BMB counts. We also related previously identified cerebral small vessel disease variants to BMBs.

Results: BMBs were detected in 3,556 of the 25,862 participants, of which 2,179 were strictly lobar and 1,293 mixed. One locus in the region reached genome-wide significance for its association with BMB (lead rs769449; odds ratio [OR] [95% confidence interval (CI)] 1.33 [1.21-1.45]; = 2.5 × 10). ε4 alleles were associated with strictly lobar (OR [95% CI] 1.34 [1.19-1.50]; = 1.0 × 10) but not with mixed BMB counts (OR [95% CI] 1.04 [0.86-1.25]; = 0.68). ε2 alleles did not show associations with BMB counts. Variants previously related to deep intracerebral hemorrhage and lacunar stroke, and a risk score of cerebral white matter hyperintensity variants, were associated with BMB.

Conclusions: Genetic variants in the region are associated with the presence of BMB, most likely due to the ε4 allele count related to a higher number of strictly lobar BMBs. Genetic predisposition to small vessel disease confers risk of BMB, indicating genetic overlap with other cerebral small vessel disease markers.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1212/WNL.0000000000010852DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7836652PMC
December 2020

Effects of White Matter Hyperintensities on 90-Day Functional Outcome after Large Vessel and Non-Large Vessel Stroke.

Cerebrovasc Dis 2020 21;49(4):419-426. Epub 2020 Jul 21.

Department of Neurosurgery, Geisinger, Danville, Pennsylvania, USA.

Introduction: White matter hyperintensity (WMH) burden is a critically important cerebrovascular phenotype related to the diagnosis and prognosis of acute ischemic stroke. The effect of WMH burden on functional outcome in large vessel occlusion (LVO) stroke has only been sparsely assessed, and direct LVO and non-LVO comparisons are currently lacking.

Material And Methods: We reviewed acute ischemic stroke patients admitted between 2009 and 2017 at a large healthcare system in the USA. Patients with LVO were identified and clinical characteristics, including 90-day functional outcomes, were assessed. Clinical brain MRIs obtained at the time of the stroke underwent quantification of WMH using a fully automated algorithm. The pipeline incorporated automated brain extraction, intensity normalization, and WMH segmentation.

Results: A total of 1,601 acute ischemic strokes with documented 90-day mRS were identified, including 353 (22%) with LVO. Among those strokes, WMH volume was available in 1,285 (80.3%) who had a brain MRI suitable for WMH quantification. Increasing WMH volume from 0 to 4 mL, age, female gender, a number of stroke risk factors, presence of LVO, and higher NIHSS at presentation all decreased the odds for a favorable outcome. Increasing WMH above 4 mL, however, was not associated with decreasing odds of favorable outcome. While WMH volume was associated with functional outcome in non-LVO stroke (p = 0.0009), this association between WMH and functional status was not statistically significant in the complete case multivariable model of LVO stroke (p = 0.0637).

Conclusion: The burden of WMH has effects on 90-day functional outcome after LVO and non-LVO strokes. Particularly, increases from no measurable WMH to 4 mL of WMH correlate strongly with the outcome. Whether this relationship of increasing WMH to worse outcome is more pronounced in non-LVO than LVO strokes deserves additional investigation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1159/000509071DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7501232PMC
November 2020

Diffusion-Weighted Imaging, MR Angiography, and Baseline Data in a Systematic Multicenter Analysis of 3,301 MRI Scans of Ischemic Stroke Patients-Neuroradiological Review Within the MRI-GENIE Study.

Front Neurol 2020 25;11:577. Epub 2020 Jun 25.

Department of Neurology and the Evelyn F. McKnight Brain Institute, Miller School of Medicine, University of Miami, Miami, FL, United States.

Magnetic resonance imaging (MRI) serves as a cornerstone in defining stroke phenotype and etiological subtype through examination of ischemic stroke lesion appearance and is therefore an essential tool in linking genetic traits and stroke. Building on baseline MRI examinations from the centralized and structured radiological assessments of ischemic stroke patients in the Stroke Genetics Network, the results of the MRI-Genetics Interface Exploration (MRI-GENIE) study are described in this work. The MRI-GENIE study included patients with symptoms caused by ischemic stroke ( = 3,301) from 12 international centers. We established and used a structured reporting protocol for all assessments. Two neuroradiologists, using a blinded evaluation protocol, independently reviewed the baseline diffusion-weighted images (DWIs) and magnetic resonance angiography images to determine acute lesion and vascular occlusion characteristics. In this systematic multicenter radiological analysis of clinical MRI from 3,301 acute ischemic stroke patients according to a structured prespecified protocol, we identified that anterior circulation infarcts were most prevalent (67.4%), that infarcts in the middle cerebral artery (MCA) territory were the most common, and that the majority of large artery occlusions 0 to 48 h from ictus were in the MCA territory. Multiple acute lesions in one or several vascular territories were common (11%). Of 2,238 patients with unilateral DWI lesions, 52.6% had left-sided infarct lateralization ( = 0.013 for χ test). This large-scale analysis of a multicenter MRI-based cohort of AIS patients presents a unique imaging framework facilitating the relationship between imaging and genetics for advancing the knowledge of genetic traits linked to ischemic stroke.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fneur.2020.00577DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7330135PMC
June 2020

Matrix Gla protein polymorphism rs1800801 associates with recurrence of ischemic stroke.

PLoS One 2020 25;15(6):e0235122. Epub 2020 Jun 25.

Department of Neurosurgery, Geisinger, Danville, PA, United States of America.

The MGP single nucleotide polymorphism (SNP) rs1800801 has previously been associated with recurrent ischemic stroke in a Spanish cohort. Here, we tested for association of this SNP with ischemic stroke recurrence in a North American Caucasian cohort. Acute ischemic stroke patients admitted between 10/2009 and 12/2016 at three hospitals within a large healthcare system in the northeastern United States that were enrolled in a healthcare system-wide exome sequencing program were retrospectively reviewed. Patients with recurrent stroke within 1 year after index event were compared to those without recurrence. Of 9,348 suspected acute ischemic strokes admitted between 10/2009 and 12/2016, 1,727 (18.5%) enrolled in the exome-sequencing program. Among those, 1,068 patients had exome sequencing completed and were eligible for inclusion. Recurrent stroke within the first year of stroke was observed in 79 patients (7.4%). In multivariable analysis, stroke prior to the index stroke (OR 9.694, 95% CI 5.793-16.224, p ≤ 0.001), pro-coagulant status (OR = 3.563, 95% CI 1.504-8.443, p = 0.004) and the AA genotype of SNP rs1800801 (OR = 2.408, 95% CI 1.079-4.389, p = 0.004) were independently associated with recurrent stroke within the first year. The AA genotype of the MGP SNP rs1800801 is associated with recurrence within the first year after ischemic stroke in North American Caucasians. Study of stroke subtypes and additional populations will be required to determine if incorporation of allelic status at this SNP into current risk scores improves prediction of recurrent ischemic stroke.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0235122PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7316322PMC
August 2020

Patient-specific Conditional Joint Models of Shape, Image Features and Clinical Indicators.

Med Image Comput Comput Assist Interv 2019 Oct 10;11767:93-101. Epub 2019 Oct 10.

Computer Science and Artificial Intelligence Lab (CSAIL), MIT, USA.

We propose and demonstrate a joint model of anatomical shapes, image features and clinical indicators for statistical shape modeling and medical image analysis. The key idea is to employ a copula model to separate the joint dependency structure from the marginal distributions of variables of interest. This separation provides flexibility on the assumptions made during the modeling process. The proposed method can handle binary, discrete, ordinal and continuous variables. We demonstrate a simple and efficient way to include binary, discrete and ordinal variables into the modeling. We build Bayesian conditional models based on observed partial clinical indicators, features or shape based on Gaussian processes capturing the dependency structure. We apply the proposed method on a stroke dataset to jointly model the shape of the lateral ventricles, the spatial distribution of the white matter hyperintensity associated with periventricular white matter disease, and clinical indicators. The proposed method yields interpretable joint models for data exploration and patient-specific statistical shape models for medical image analysis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/978-3-030-32251-9_11DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7267042PMC
October 2019

White matter hyperintensity burden in acute stroke patients differs by ischemic stroke subtype.

Neurology 2020 07 3;95(1):e79-e88. Epub 2020 Jun 3.

From the Department of Neurology (A.-K.G., M.D.S., K.L.D., M.N., J.R., O.W., N.S.R.), Massachusetts General Hospital, Harvard Medical School, Boston; Program in Medical and Population Genetics (A.K.-G, J.R.), Broad Institute of MIT and Harvard; Computer Science and Artificial Intelligence Lab (M.D.S., A.V.D., R. Sridharan, P.G.), Massachusetts Institute of Technology, Cambridge; Department of Population Health Sciences (M.D.S.), German Centre for Neurodegenerative Diseases, Bonn, Germany; Athinoula A. Martinos Center for Biomedical Imaging (A.V.D., R.I., E.C.M., S.J.T.M., J.R., O.W.), Department of Radiology, Massachusetts General Hospital, Charlestown; Division of Endocrinology, Diabetes and Nutrition (H.X., P.F.M., B.D.M.), Department of Medicine, University of Maryland School of Medicine; Department of Neurology (J.W.C., S.J.K.), University of Maryland School of Medicine and Veterans Affairs Maryland Health Care System, Baltimore; Department of Neurology (E.G.-S., J.J.-C.), Neurovascular Research Group, IMIM-Hospital del Mar (Institut Hospital del Mar d'Investigacions Mèdiques), Universitat Autonoma de Barcelona, Spain; Institute of Biomedicine (C.J.), Sahlgrenska Academy at University of Gothenburg, Sweden; Department of Neurology and Rehabilitation Medicine (D.O.K., D.W.), University of Cincinnati College of Medicine, OH; KU Leuven-University of Leuven (R.L.), Department of Neurosciences, Experimental Neurology; VIB (R.L.), Vesalius Research Center, Laboratory of Neurobiology, University Hospitals Leuven, Department of Neurology, Belgium; Department of Clinical Sciences Lund (J.W., A.L.), Neurology, Lund University; Department of Neurology and Rehabilitation Medicine (A.L.), Neurology, Skåne University Hospital, Lund, Sweden; Department of Neurology (T.R., R.L.S.), Miller School of Medicine, University of Miami, The Evelyn F. McKnight Brain Institute, FL; Department of Neurology (R. Schmidt), Clinical Division of Neurogeriatrics, Medical University Graz, Austria; Institute of Cardiovascular Research (P.S.), Royal Holloway University of London, Egham, UK; Ashford and St Peter's Hospital (P.S.), UK; Department of Neurology (A.S.), Jagiellonian University Medical College, Krakow, Poland; Stroke Division (V.T.), Florey Institute of Neuroscience and Mental Health, University of Melbourne Heidelberg; Department of Neurology (V.T.), Austin Health, Heidelberg, Victoria, Australia; Departments of Neurology and Public Health Sciences (B.B.W.), University of Virginia, Charlottesville; Center for Genomic Medicine (J.R.), Massachusetts General Hospital; Henry and Allison McCance Center for Brain Health (J.R.), Boston, MA; and Department of Neurology (J.F.M.), Mayo Clinic, Jacksonville, FL.

Objective: To examine etiologic stroke subtypes and vascular risk factor profiles and their association with white matter hyperintensity (WMH) burden in patients hospitalized for acute ischemic stroke (AIS).

Methods: For the MRI Genetics Interface Exploration (MRI-GENIE) study, we systematically assembled brain imaging and phenotypic data for 3,301 patients with AIS. All cases underwent standardized web tool-based stroke subtyping with the Causative Classification of Ischemic Stroke (CCS). WMH volume (WMHv) was measured on T2 brain MRI scans of 2,529 patients with a fully automated deep-learning trained algorithm. Univariable and multivariable linear mixed-effects modeling was carried out to investigate the relationship of vascular risk factors with WMHv and CCS subtypes.

Results: Patients with AIS with large artery atherosclerosis, major cardioembolic stroke, small artery occlusion (SAO), other, and undetermined causes of AIS differed significantly in their vascular risk factor profile (all < 0.001). Median WMHv in all patients with AIS was 5.86 cm (interquartile range 2.18-14.61 cm) and differed significantly across CCS subtypes ( < 0.0001). In multivariable analysis, age, hypertension, prior stroke, smoking (all < 0.001), and diabetes mellitus ( = 0.041) were independent predictors of WMHv. When adjusted for confounders, patients with SAO had significantly higher WMHv compared to those with all other stroke subtypes ( < 0.001).

Conclusion: In this international multicenter, hospital-based cohort of patients with AIS, we demonstrate that vascular risk factor profiles and extent of WMH burden differ by CCS subtype, with the highest lesion burden detected in patients with SAO. These findings further support the small vessel hypothesis of WMH lesions detected on brain MRI of patients with ischemic stroke.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1212/WNL.0000000000009728DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7371377PMC
July 2020

Brain Volume: An Important Determinant of Functional Outcome After Acute Ischemic Stroke.

Mayo Clin Proc 2020 05;95(5):955-965

Division of Neurocritical Care and Emergency Neurology, Department of Neurology, Helsinki University Central Hospital, Helsinki, Finland.

Objective: To determine whether brain volume is associated with functional outcome after acute ischemic stroke (AIS).

Patients And Methods: This study was conducted between July 1, 2014, and March 16, 2019. We analyzed cross-sectional data of the multisite, international hospital-based MRI-Genetics Interface Exploration study with clinical brain magnetic resonance imaging obtained on admission for index stroke and functional outcome assessment. Poststroke outcome was determined using the modified Rankin Scale score (0-6; 0 = asymptomatic; 6 = death) recorded between 60 and 190 days after stroke. Demographic characteristics and other clinical variables including acute stroke severity (measured as National Institutes of Health Stroke Scale score), vascular risk factors, and etiologic stroke subtypes (Causative Classification of Stroke system) were recorded during index admission.

Results: Utilizing the data from 912 patients with AIS (mean ± SD age, 65.3±14.5 years; male, 532 [58.3%]; history of smoking, 519 [56.9%]; hypertension, 595 [65.2%]) in a generalized linear model, brain volume (per 155.1 cm) was associated with age (β -0.3 [per 14.4 years]), male sex (β 1.0), and prior stroke (β -0.2). In the multivariable outcome model, brain volume was an independent predictor of modified Rankin Scale score (β -0.233), with reduced odds of worse long-term functional outcomes (odds ratio, 0.8; 95% CI, 0.7-0.9) in those with larger brain volumes.

Conclusion: Larger brain volume quantified on clinical magnetic resonance imaging of patients with AIS at the time of stroke purports a protective mechanism. The role of brain volume as a prognostic, protective biomarker has the potential to forge new areas of research and advance current knowledge of the mechanisms of poststroke recovery.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.mayocp.2020.01.027DOI Listing
May 2020

Multi-atlas image registration of clinical data with automated quality assessment using ventricle segmentation.

Med Image Anal 2020 07 18;63:101698. Epub 2020 Apr 18.

J. Philip Kistler Stroke Research Center, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, USA; Computer Science and Artificial Intelligence Lab, Massachusetts Institute of Technology, Cambridge, USA; Department of Population Health Sciences, German Centre for Neurodegenerative Diseases (DZNE), Germany. Electronic address:

Registration is a core component of many imaging pipelines. In case of clinical scans, with lower resolution and sometimes substantial motion artifacts, registration can produce poor results. Visual assessment of registration quality in large clinical datasets is inefficient. In this work, we propose to automatically assess the quality of registration to an atlas in clinical FLAIR MRI scans of the brain. The method consists of automatically segmenting the ventricles of a given scan using a neural network, and comparing the segmentation to the atlas ventricles propagated to image space. We used the proposed method to improve clinical image registration to a general atlas by computing multiple registrations - one directly to the general atlas and others via different age-specific atlases - and then selecting the registration that yielded the highest ventricle overlap. Finally, as an example application of the complete pipeline, a voxelwise map of white matter hyperintensity burden was computed using only the scans with registration quality above a predefined threshold. Methods were evaluated in a single-site dataset of more than 1000 scans, as well as a multi-center dataset comprising 142 clinical scans from 12 sites. The automated ventricle segmentation reached a Dice coefficient with manual annotations of 0.89 in the single-site dataset, and 0.83 in the multi-center dataset. Registration via age-specific atlases could improve ventricle overlap compared to a direct registration to the general atlas (Dice similarity coefficient increase up to 0.15). Experiments also showed that selecting scans with the registration quality assessment method could improve the quality of average maps of white matter hyperintensity burden, instead of using all scans for the computation of the white matter hyperintensity map. In this work, we demonstrated the utility of an automated tool for assessing image registration quality in clinical scans. This image quality assessment step could ultimately assist in the translation of automated neuroimaging pipelines to the clinic.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.media.2020.101698DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7275913PMC
July 2020

The ENIGMA Stroke Recovery Working Group: Big data neuroimaging to study brain-behavior relationships after stroke.

Hum Brain Mapp 2020 Apr 20. Epub 2020 Apr 20.

Department of Health Sciences and Research, Medical University of South Carolina, Charleston, South Carolina, USA.

The goal of the Enhancing Neuroimaging Genetics through Meta-Analysis (ENIGMA) Stroke Recovery working group is to understand brain and behavior relationships using well-powered meta- and mega-analytic approaches. ENIGMA Stroke Recovery has data from over 2,100 stroke patients collected across 39 research studies and 10 countries around the world, comprising the largest multisite retrospective stroke data collaboration to date. This article outlines the efforts taken by the ENIGMA Stroke Recovery working group to develop neuroinformatics protocols and methods to manage multisite stroke brain magnetic resonance imaging, behavioral and demographics data. Specifically, the processes for scalable data intake and preprocessing, multisite data harmonization, and large-scale stroke lesion analysis are described, and challenges unique to this type of big data collaboration in stroke research are discussed. Finally, future directions and limitations, as well as recommendations for improved data harmonization through prospective data collection and data management, are provided.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/hbm.25015DOI Listing
April 2020

Atrial Fibrillation Risk and Discrimination of Cardioembolic From Noncardioembolic Stroke.

Stroke 2020 05 7;51(5):1396-1403. Epub 2020 Apr 7.

Cardiac Arrhythmia Service, Division of Cardiology, (P.T.E., S.A.L.), Massachusetts General Hospital, Boston.

Background and Purpose- Classification of stroke as cardioembolic in etiology can be challenging, particularly since the predominant cause, atrial fibrillation (AF), may not be present at the time of stroke. Efficient tools that discriminate cardioembolic from noncardioembolic strokes may improve care as anticoagulation is frequently indicated after cardioembolism. We sought to assess and quantify the discriminative power of AF risk as a classifier for cardioembolism in a real-world population of patients with acute ischemic stroke. Methods- We performed a cross-sectional analysis of a multi-institutional sample of patients with acute ischemic stroke. We systematically adjudicated stroke subtype and examined associations between AF risk using CHADS-VASc, Cohorts for Heart and Aging Research in Genomic Epidemiology-AF score, and the recently developed Electronic Health Record-Based AF score, and cardioembolic stroke using logistic regression. We compared the ability of AF risk to discriminate cardioembolism by calculating C statistics and sensitivity/specificity cutoffs for cardioembolic stroke. Results- Of 1431 individuals with ischemic stroke (age, 65±15; 40% women), 323 (22.6%) had cardioembolism. AF risk was significantly associated with cardioembolism (CHADS-VASc: odds ratio [OR] per SD, 1.69 [95% CI, 1.49-1.93]; Cohorts for Heart and Aging Research in Genomic Epidemiology-AF score: OR, 2.22 [95% CI, 1.90-2.60]; electronic Health Record-Based AF: OR, 2.55 [95% CI, 2.16-3.04]). Discrimination was greater for Cohorts for Heart and Aging Research in Genomic Epidemiology-AF score (C index, 0.695 [95% CI, 0.663-0.726]) and Electronic Health Record-Based AF score (0.713 [95% CI, 0.681-0.744]) versus CHADS-VASc (C index, 0.651 [95% CI, 0.619-0.683]). Examination of AF scores across a range of thresholds indicated that AF risk may facilitate identification of individuals at low likelihood of cardioembolism (eg, negative likelihood ratios for Electronic Health Record-Based AF score ranged 0.31-0.10 at sensitivity thresholds 0.90-0.99). Conclusions- AF risk scores associate with cardioembolic stroke and exhibit moderate discrimination. Utilization of AF risk scores at the time of stroke may be most useful for identifying individuals at low probability of cardioembolism. Future analyses are warranted to assess whether stroke subtype classification can be enhanced to improve outcomes in undifferentiated stroke.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1161/STROKEAHA.120.028837DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7188588PMC
May 2020
-->