Publications by authors named "Sanjeev Bhavnani"

31 Publications

Predicting cardiac disease from interactions of simultaneously-acquired hemodynamic and cardiac signals.

Comput Methods Programs Biomed 2021 Feb 7;202:105970. Epub 2021 Feb 7.

CorVista Health(†), 160 Bloor St. East, Suite 910, Toronto, ON, Canada. Electronic address:

Background And Objective: Coronary artery disease (CAD) and heart failure are the most common cardiovascular diseases. Non-invasive diagnostic testing for CAD requires radiation, heart rate acceleration, and imaging infrastructure. Early detection of left ventricular dysfunction is critical in heart failure management, the best measure of which is an elevated left ventricular end-diastolic pressure (LVEDP) that can only be measured using invasive cardiac catheterization. There exists a need for non-invasive, safe, and fast diagnostic testing for CAD and elevated LVEDP. This research employs nonlinear dynamics to assess for significant CAD and elevated LVEDP using non-invasively acquired photoplethysmographic (PPG) and three-dimensional orthogonal voltage gradient (OVG) signals. PPG (variations of the blood volume perfusing the tissue) and OVG (mechano-electrical activity of the heart) signals represent the dynamics of the cardiovascular system.

Methods: PPG and OVG were simultaneously acquired from two cohorts, (i) symptomatic subjects that underwent invasive cardiac catheterization, the gold standard test (408 CAD positive with stenosis≥ 70% and 186 with LVEDP≥ 20 mmHg) and (ii) asymptomatic healthy controls (676). A set of Poincaré-based synchrony features were developed to characterize the interactions between the OVG and PPG signals. The extracted features were employed to train machine learning models for CAD and LVEDP. Five-fold cross-validation was used and the best model was selected based on the average area under the receiver operating characteristic curve (AUC) across 100 runs, then assessed using a hold-out test set.

Results: The Elastic Net model developed on the synchrony features can effectively classify CAD positive subjects from healthy controls with an average validation AUC=0.90±0.03 and an AUC= 0.89 on the test set. The developed model for LVEDP can discriminate subjects with elevated LVEDP from healthy controls with an average validation AUC=0.89±0.03 and an AUC=0.89 on the test set. The feature contributions results showed that the selection of a proper registration point for Poincaré analysis is essential for the development of predictive models for different disease targets.

Conclusions: Nonlinear features from simultaneously-acquired signals used as inputs to machine learning can assess CAD and LVEDP safely and accurately with an easy-to-use, portable device, utilized at the point-of-care without radiation, contrast, or patient preparation.
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http://dx.doi.org/10.1016/j.cmpb.2021.105970DOI Listing
February 2021

Digital Health: Opportunities and Challenges to Develop the Next-Generation Technology-Enabled Models of Cardiovascular Care.

Methodist Debakey Cardiovasc J 2020 Oct-Dec;16(4):296-303

SCRIPPS CLINIC-PREBYS CARDIOVASCULAR INSTITUTE, SAN DIEGO, CALIFORNIA.

The wide gap between the development of new healthcare technologies and their integration into clinical practice argues for a deeper understanding of how effective quality improvement can be designed to meet the needs of patients and their clinical teams. The COVID-19 pandemic has forced us to address this gap and create long-term strategies to bridge it. On the one hand, it has enabled the rapid implementation of telehealth. On the other hand, it has raised important questions about our preparedness to adopt and employ new digital tools as part of a new process of care. While healthcare organizations are seeking to improve the quality of care by integrating innovations in digital health, they must also address key issues such as patient experience, develop clinical decision support systems that analyze digital health data trends, and create efficient clinical workflows. Given the breadth of such requirements, embracing new technologies as a core competency of a modern healthcare system introduces a host of questions, such as "How best do patients participate in digital health programs that promote behavioral changes and mitigate risk?" and "What type of data analytics are required that enable a deeper understanding of disease phenotypes and corresponding treatment decisions?" This review presents the challenges in implementing digital health technology and discusses how patient-centered digital health programs are designed within real-world models of remote monitoring. It also provides a framework for developing new devices and wearables for the next generation of data-driven, technology-enabled cardiovascular care.
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http://dx.doi.org/10.14797/mdcj-16-4-296DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7812856PMC
February 2021

Gerotechnology for Older Adults With Cardiovascular Diseases: JACC State-of-the-Art Review.

J Am Coll Cardiol 2020 12;76(22):2650-2670

Prebys Cardiovascular Institute, Scripps Clinic & Research Foundation, San Diego, California.

The growing population of older adults (age ≥65 years) is expected to lead to higher rates of cardiovascular disease. The expansion of digital health (encompassing telehealth, telemedicine, mobile health, and remote patient monitoring), Internet access, and cellular technologies provides an opportunity to enhance patient care and improve health outcomes-opportunities that are particularly relevant during the current coronavirus disease-2019 pandemic. Insufficient dexterity, visual impairment, and cognitive dysfunction, found commonly in older adults should be taken into consideration in the development and utilization of existing technologies. If not implemented strategically and appropriately, these can lead to inequities propagating digital divides among older adults, across disease severities and socioeconomic distributions. A systematic approach, therefore, is needed to study and implement digital health strategies in older adults. This review will focus on current knowledge of the benefits, barriers, and use of digital health in older adults for cardiovascular disease management.
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http://dx.doi.org/10.1016/j.jacc.2020.09.606DOI Listing
December 2020

Cardiac Stress Testing After Coronary Revascularization.

Am J Cardiol 2020 12 16;136:9-14. Epub 2020 Sep 16.

Terrence Donnelly Heart Centre, St Michael's Hospital, University of Toronto, Toronto, Ontario, Canada; Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada. Electronic address:

Unless prompted by symptoms or change in clinical status, the appropriate use criteria consider cardiac stress testing (CST) within 2 years of percutaneous coronary intervention (PCI) and 5 years of coronary artery bypass grafting (CABG) to be rarely appropriate. Little is known regarding use and yield of CST after PCI or CABG. We studied 39,648 patients treated with coronary revascularization (29,497 PCI; 10,151 CABG) between April 2004 and March 2012 in Alberta, Canada. Frequency of CST between 60 days and 2 years after revascularization was determined from linked provincial databases. Yield was defined as subsequent rates of coronary angiography and revascularization after CST. Post PCI, 14,195 (48.1%) patients underwent CST between 60 days and 2 years, while post CABG, 4,469 (44.0%) patients underwent CST. Compared with patients not undergoing CST, patients undergoing CST were more likely to be of younger age, reside in an urban area, have higher neighborhood median household income, but less medical comorbidities. Among PCI patients undergoing CST, 5.2% underwent subsequent coronary angiography, and 2.6% underwent repeat revascularization within 60 days of CST. Rates of coronary angiography and repeat revascularization post-CST among CABG patients were 3.6% and 1.1%, respectively. Approximately one-half of patients undergo CST within 2 years of PCI or CABG in Alberta, Canada. Yield of CST is low, with only 1 out of 38 tested post-PCI patients and 1 out of 91 tested post-CABG patients undergoing further revascularization. In conclusion, additional research is required to determine patients most likely to benefit from CST after revascularization.
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http://dx.doi.org/10.1016/j.amjcard.2020.08.051DOI Listing
December 2020

Toward precision health: applying artificial intelligence analytics to digital health biometric datasets.

Per Med 2020 07 26;17(4):307-316. Epub 2020 Jun 26.

Division of Cardiology, Healthcare Innovation & Practice Transformation Laboratory, Scripps Clinic, San Diego, CA 92037, USA.

The rapid development of digital health devices has enabled patients to engage in their care to an unprecedented degree and holds the possibility of significantly improving the diagnosis, treatment and monitoring of many medical conditions. Combined with the emergence of artificial intelligence algorithms, biometric datasets produced from these digital health devices present new opportunities to create precision-based, personalized approaches for healthcare delivery. For effective implementation of such innovations to patient care, clinicians will require an understanding of the types of datasets produced from digital health technologies; the types of analytic methods including feature selection, convolution neural networking, and deep learning that can be used to analyze digital data; and how the interpretation of these findings are best translated to patient care. In this perspective, we aim to provide the groundwork for clinicians to be able to apply artificial intelligence to this transformation of healthcare.
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http://dx.doi.org/10.2217/pme-2019-0113DOI Listing
July 2020

Postoperative Remote Automated Monitoring and Virtual Hospital-to-Home Care System Following Cardiac and Major Vascular Surgery: User Testing Study.

J Med Internet Res 2020 03 18;22(3):e15548. Epub 2020 Mar 18.

Population Health Research Institute, Hamilton, ON, Canada.

Background: Cardiac and major vascular surgeries are common surgical procedures associated with high rates of postsurgical complications and related hospital readmission. In-hospital remote automated monitoring (RAM) and virtual hospital-to-home patient care systems have major potential to improve patient outcomes following cardiac and major vascular surgery. However, the science of deploying and evaluating these systems is complex and subject to risk of implementation failure.

Objective: As a precursor to a randomized controlled trial (RCT), this user testing study aimed to examine user performance and acceptance of a RAM and virtual hospital-to-home care intervention, using Philip's Guardian and Electronic Transition to Ambulatory Care (eTrAC) technologies, respectively.

Methods: Nurses and patients participated in systems training and individual case-based user testing at two participating sites in Canada and the United Kingdom. Participants were video recorded and asked to think aloud while completing required user tasks and while being rated on user performance. Feedback was also solicited about the user experience, including user satisfaction and acceptance, through use of the Net Promoter Scale (NPS) survey and debrief interviews.

Results: A total of 37 participants (26 nurses and 11 patients) completed user testing. The majority of nurse and patient participants were able to complete most required tasks independently, demonstrating comprehension and retention of required Guardian and eTrAC system workflows. Tasks which required additional prompting by the facilitator, for some, were related to the use of system features that enable continuous transmission of patient vital signs (eg, pairing wireless sensors to the patient) and assigning remote patient monitoring protocols. NPS scores by user group (nurses using Guardian: mean 8.8, SD 0.89; nurses using eTrAC: mean 7.7, SD 1.4; patients using eTrAC: mean 9.2, SD 0.75), overall NPS scores, and participant debrief interviews indicated nurse and patient satisfaction and acceptance of the Guardian and eTrAC systems. Both user groups stressed the need for additional opportunities to practice in order to become comfortable and proficient in the use of these systems.

Conclusions: User testing indicated a high degree of user acceptance of Philips' Guardian and eTrAC systems among nurses and patients. Key insights were provided that informed refinement of clinical workflow training and systems implementation. These results were used to optimize workflows before the launch of an international RCT of in-hospital RAM and virtual hospital-to-home care for patients undergoing cardiac and major vascular surgery.
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http://dx.doi.org/10.2196/15548DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7113803PMC
March 2020

What do physicians need to know in order to 'prescribe' mobile applications to patients with cardiovascular disease?

Per Med 2019 07 17;16(4):263-268. Epub 2019 Jul 17.

Department of Medicine, McMaster University, Hamilton, ON, L8S 4L8, Canada.

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http://dx.doi.org/10.2217/pme-2019-0015DOI Listing
July 2019

Privacy-Preserving Generative Deep Neural Networks Support Clinical Data Sharing.

Circ Cardiovasc Qual Outcomes 2019 07 9;12(7):e005122. Epub 2019 Jul 9.

Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia. (C.W., C.S.G.).

Background: Data sharing accelerates scientific progress but sharing individual-level data while preserving patient privacy presents a barrier.

Methods And Results: Using pairs of deep neural networks, we generated simulated, synthetic participants that closely resemble participants of the SPRINT trial (Systolic Blood Pressure Trial). We showed that such paired networks can be trained with differential privacy, a formal privacy framework that limits the likelihood that queries of the synthetic participants' data could identify a real a participant in the trial. Machine learning predictors built on the synthetic population generalize to the original data set. This finding suggests that the synthetic data can be shared with others, enabling them to perform hypothesis-generating analyses as though they had the original trial data.

Conclusions: Deep neural networks that generate synthetic participants facilitate secondary analyses and reproducible investigation of clinical data sets by enhancing data sharing while preserving participant privacy.
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http://dx.doi.org/10.1161/CIRCOUTCOMES.118.005122DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7041894PMC
July 2019

Virtual Care 2.0-a Vision for the Future of Data-Driven Technology-Enabled Healthcare.

Curr Treat Options Cardiovasc Med 2019 Apr 15;21(5):21. Epub 2019 Apr 15.

Department of Medicine, Divisions of General Internal Medicine and Biomedical Informatics, Chief Medical Information Officer of Population Health, University of California San Diego, 9560 Towne Centre Drive, San Diego, CA, 92121, USA.

A busy community cardiologist finished reading eight echocardiograms over lunch and started clinic at 1 pm. As three patients waited, "Jane," a 45-year-old graphic designer was seen for "skipped heart beat." She works about 50 h a week, exercises at the local gym, and enjoys eating a healthy diet. About 4 months ago Jane began experiencing her heart "skipping beats." She initially attributed the symptoms to long hours in the office and caffeine. But, over the holiday, her brother purchased a smart watch and she began digitally recording her cardiac rhythm. About a month ago, the device detected possible atrial fibrillation, so she called and scheduled this visit for a cardiology consultation. Upon that visitation, she and her physician reviewed the device readings. While it appeared to be an irregular rhythm, before either considered a treatment plan, they began to ask questions ranging from the following: "Is this an accurate diagnosis?" "What other data are available to better understand the risk of a cardiac arrhythmia?" "How is this data analyzed so that the best treatment plan can be made?" "And, what type of clinical decision support system is required to 'virtually' monitor people like me using digital health devices to improve the efficiency and quality of care delivered in population health?"
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http://dx.doi.org/10.1007/s11936-019-0727-2DOI Listing
April 2019

Postoperative Remote Automated Monitoring: Need for and State of the Science.

Can J Cardiol 2018 07 25;34(7):850-862. Epub 2018 Apr 25.

McMaster University, Faculty of Health Sciences, Hamilton, Ontario, Canada; Population Health Research Institute, McMaster University and Hamilton Health Sciences, Hamilton, Ontario, Canada.

Worldwide, more than 230 million adults have major noncardiac surgery each year. Although surgery can improve quality and duration of life, it can also precipitate major complications. Moreover, a substantial proportion of deaths occur after discharge. Current systems for monitoring patients postoperatively, on surgical wards and after transition to home, are inadequate. On the surgical ward, vital signs evaluation usually occurs only every 4-8 hours. Reduced in-hospital ward monitoring, followed by no vital signs monitoring at home, leads to thousands of cases of undetected/delayed detection of hemodynamic compromise. In this article we review work to date on postoperative remote automated monitoring on surgical wards and strategy for advancing this field. Key considerations for overcoming current barriers to implementing remote automated monitoring in Canada are also presented.
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http://dx.doi.org/10.1016/j.cjca.2018.04.021DOI Listing
July 2018

From false-positives to technological Darwinism: controversies in digital health.

Per Med 2018 07 22;15(4):247-250. Epub 2018 Jun 22.

Division of Cardiology, Emory University School of Medicine, Atlanta, GA, USA.

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http://dx.doi.org/10.2217/pme-2018-0033DOI Listing
July 2018

Data Sharing and Cardiology: Platforms and Possibilities.

J Am Coll Cardiol 2017 Dec;70(24):3018-3025

Section of Cardiovascular Medicine, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut; Department of Health Policy and Management, Yale School of Public Health, New Haven, Connecticut; Center for Outcomes Research and Evaluation, Yale-New Haven Hospital, New Haven, Connecticut. Electronic address:

Sharing deidentified patient-level research data presents immense opportunities to all stakeholders involved in cardiology research and practice. Sharing data encourages the use of existing data for knowledge generation to improve practice, while also allowing for validation of disseminated research. In this review, we discuss key initiatives and platforms that have helped to accelerate progress toward greater sharing of data. These efforts are being prompted by government, universities, philanthropic sponsors of research, major industry players, and collaborations among some of these entities. As data sharing becomes a more common expectation, policy changes will be required to encourage and assist data generators with the process of sharing the data they create. Patients also will need access to their own data and to be empowered to share those data with researchers. Although medicine still lags behind other fields in achieving data sharing's full potential, cardiology research has the potential to lead the way.
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http://dx.doi.org/10.1016/j.jacc.2017.10.037DOI Listing
December 2017

Coronary risk equivalence of diabetes assessed by SPECT-MPI.

J Nucl Cardiol 2019 08 6;26(4):1093-1102. Epub 2017 Dec 6.

Gagnon Cardiovascular Institute, Morristown Medical Center, Morristown, NJ, USA.

Background: Several publications and guidelines designate diabetes mellitus (DM) as a coronary artery disease (CAD) risk equivalent. The aim of this investigation was to examine DM cardiac risk equivalence from the perspective of stress SPECT myocardial perfusion imaging (MPI).

Methods And Results: We examined cardiovascular outcomes (cardiac death or nonfatal MI) of 17,499 patients referred for stress SPECT-MPI. Patients were stratified into four categories: non-DM without CAD, non-DM with CAD, DM without CAD, and DM with CAD, and normal or abnormal perfusion. Cardiac events occurred in 872 (5%), with event-free survival best among non-DM without CAD, worst in DM with CAD, and intermediate in DM without CAD, and non-DM with CAD. After multivariate adjustment, risk remained comparable between DM without CAD and non-DM with CAD [AHR 1.0 (95% CI 0.84-1.28), P =0.74]. Annualized event rates for normal subjects were 1.4% and 1.6% for non-DM with CAD and DM without CAD, respectively (P = 0.48) and 3.5% (P = 0.95) for both abnormal groups. After multivariate adjustment, outcomes were comparable within normal [AHR 1.4 (95% CI 0.98-1.96) P = 0.06] and abnormal [AHR 1.1 (95% CI 0.83-1.50) P = 0.49] MPI.

Conclusions: Diabetic patients without CAD have comparable risk of cardiovascular events as non-diabetic patients with CAD after stratification by MPI results. These findings support diabetes as a CAD equivalent and suggest that MPI provides additional prognostic information in such patients.
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http://dx.doi.org/10.1007/s12350-017-1114-6DOI Listing
August 2019

Population-Based Study on Patterns of Cardiac Stress Testing After Percutaneous Coronary Intervention.

Circ Cardiovasc Qual Outcomes 2017 Oct;10(10)

From the Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada (A.B.); Terrence Donnelly Heart Center, St. Michael's Hospital, University of Toronto, Ontario, Canada (A.B., A.N.C., A.T.Y., A.D., S.G.G.); Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada (M.E., M.K., H.C.W., D.T.K.); Division of Cardiology, Scripps Clinic and Research Institute, San Diego, CA (S.P.B.); Schulich Heart Centre, Sunnybrook Health Sciences Centre, University of Toronto, Ontario, Canada (H.C.W., D.T.K.); Peter Munk Cardiac Center of the University Health Network, University of Toronto, Ontario, Canada (S.B.); Women's College Hospital Institute for Health Systems Solutions and Virtual Care, Toronto, Ontario, Canada (S.B.); and Canadian VIGOUR Centre, University of Alberta, Edmonton, Canada (P.K., S.G.G.).

Background: The appropriate use criteria considers cardiac stress testing within 2 years after percutaneous coronary intervention (PCI) to be rarely appropriate, unless prompted by symptoms or change in clinical status. Little is known about the patterns of cardiac stress testing after PCI in the single-payer Canadian healthcare system, where mechanisms for reimbursement are different from the United States.

Methods And Results: Frequency and timing of cardiac stress testing within 2 years of PCI performed between April 2004 and March 2013 in Ontario, Canada, was determined from linked provincial databases. Subsequent rates of coronary angiography and revascularization after stress testing were ascertained. Of the 112 691 patients with PCI, 67 442 (59.8%) underwent at least 1 stress test, with 38 267 (34.0%) undergoing repeat stress testing (ie, >1 stress test) within 2 years. Patients who underwent stress testing were younger, had less medical comorbidities, were more likely to reside in urban areas, and had higher incomes. Spikes in incidence of repeat stress testing were observed at 3 to 4 months, 6 to 7 months, and 12 to 13 months after the prior stress test. Of those tested, only 5.9% underwent subsequent coronary angiography, and only 3.1% underwent repeat revascularization within 60 days of stress testing.

Conclusions: More than half of all patients undergo cardiac stress testing within 2 years of PCI, with one third undergoing repeat stress tests. Only 1 of 30 tested patients underwent repeat revascularization. These findings reinforce the appropriate use criteria recommendations against routine stress testing after PCI. Further work is needed to aid with the selection of patients most likely to benefit from stress testing after PCI.
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http://dx.doi.org/10.1161/CIRCOUTCOMES.117.003660DOI Listing
October 2017

A Randomized Trial of Pocket-Echocardiography Integrated Mobile Health Device Assessments in Modern Structural Heart Disease Clinics.

JACC Cardiovasc Imaging 2018 04 5;11(4):546-557. Epub 2017 Oct 5.

West Virginia University Heart and Vascular Institute at West Virginia University School of Medicine, Morgantown, West Virginia. Electronic address:

Objectives: This study sought to determine whether mobile health (mHealth) device assessments used as clinical decision support tools at the point-of-care can reduce the time to treatment and improve long-term outcomes among patients with rheumatic and structural heart diseases (SHD).

Background: Newly developed smartphone-connected mHealth devices represent promising methods to diagnose common diseases in resource-limited areas; however, the impact of technology-based care on long-term outcomes has not been rigorously evaluated.

Methods: A total of 253 patients with SHD were randomized to an initial diagnostic assessment with wireless devices in mHealth clinics (n = 139) or to standard-care (n = 114) in India. mHealth clinics were equipped with point-of-care devices including pocket-echocardiography, smartphone-connected-electrocardiogram blood pressure and oxygen measurements, activity monitoring, and portable brain natriuretic peptide laboratory testing. All individuals underwent comprehensive transthoracic echocardiography to assess the severity of SHD. The primary endpoint was the time to referral for therapy with percutaneous valvuloplasty or surgical valve replacement. Secondary endpoints included the probability of a cardiovascular hospitalization and/or death over 1 year.

Results: An initial mHealth assessment was associated with a shorter time to referral for valvuloplasty and/or valve replacement (83 ± 79 days vs. 180 ± 101 days; p <0.001) and was associated with an increased probability for valvuloplasty/valve replacement compared to standard-care (34% vs. 32%; adjusted hazard ratio: 1.54; 95% CI: 0.96 to 2.47; p = 0.07). Patients randomized to mHealth were associated with a lower risk of a hospitalization and/or death on follow-up (15% vs. 28%, adjusted hazard ratio: 0.41; 95% CI: 0.21 to 0.83; p = 0.013).

Conclusions: An initial mHealth diagnostic strategy was associated with a shorter time to definitive therapy among patients with SHD in a resource-limited area and was associated with improved outcomes. (A Randomized Trial of Pocket-Echocardiography Integrated Mobile Health Device Assessments in Modern Structural Heart Disease Clinics; NCT02881398).
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http://dx.doi.org/10.1016/j.jcmg.2017.06.019DOI Listing
April 2018

Data Science in Healthcare: Implications for Early Career Investigators.

Circ Cardiovasc Qual Outcomes 2016 11 8;9(6):683-687. Epub 2016 Nov 8.

From the Division of Cardiology, Scripps Clinic and Research Institute, San Diego, CA (S.P.B.); Division of Cardiology, Vanderbilt University, Nashville, TN (D.M.); and Terrence Donnelly Heart Center, St. Michael's Hospital, University of Toronto, Ontario, Canada (A.B.).

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http://dx.doi.org/10.1161/CIRCOUTCOMES.116.003081DOI Listing
November 2016

Technology-Enabled Remote Monitoring and Self-Management - Vision for Patient Empowerment Following Cardiac and Vascular Surgery: User Testing and Randomized Controlled Trial Protocol.

JMIR Res Protoc 2016 Aug 1;5(3):e149. Epub 2016 Aug 1.

McMaster University, Hamiltion, ON, Canada.

Background: Tens of thousands of cardiac and vascular surgeries (CaVS) are performed on seniors in Canada and the United Kingdom each year to improve survival, relieve disease symptoms, and improve health-related quality of life (HRQL). However, chronic postsurgical pain (CPSP), undetected or delayed detection of hemodynamic compromise, complications, and related poor functional status are major problems for substantial numbers of patients during the recovery process. To tackle this problem, we aim to refine and test the effectiveness of an eHealth-enabled service delivery intervention, TecHnology-Enabled remote monitoring and Self-MAnagemenT-VIsion for patient EmpoWerment following Cardiac and VasculaR surgery (THE SMArTVIEW, CoVeRed), which combines remote monitoring, education, and self-management training to optimize recovery outcomes and experience of seniors undergoing CaVS in Canada and the United Kingdom.

Objective: Our objectives are to (1) refine SMArTVIEW via high-fidelity user testing and (2) examine the effectiveness of SMArTVIEW via a randomized controlled trial (RCT).

Methods: CaVS patients and clinicians will engage in two cycles of focus groups and usability testing at each site; feedback will be elicited about expectations and experience of SMArTVIEW, in context. The data will be used to refine the SMArTVIEW eHealth delivery program. Upon transfer to the surgical ward (ie, post-intensive care unit [ICU]), 256 CaVS patients will be reassessed postoperatively and randomly allocated via an interactive Web randomization system to the intervention group or usual care. The SMArTVIEW intervention will run from surgical ward day 2 until 8 weeks following surgery. Outcome assessments will occur on postoperative day 30; at week 8; and at 3, 6, 9, and 12 months. The primary outcome is worst postop pain intensity upon movement in the previous 24 hours (Brief Pain Inventory-Short Form), averaged across the previous 14 days. Secondary outcomes include a composite of postoperative complications related to hemodynamic compromise-death, myocardial infarction, and nonfatal stroke- all-cause mortality and surgical site infections, functional status (Medical Outcomes Study Short Form-12), depressive symptoms (Geriatric Depression Scale), health service utilization-related costs (health service utilization data from the Institute for Clinical Evaluative Sciences data repository), and patient-level cost of recovery (Ambulatory Home Care Record). A linear mixed model will be used to assess the effects of the intervention on the primary outcome, with an a priori contrast of weekly average worst pain intensity upon movement to evaluate the primary endpoint of pain at 8 weeks postoperation. We will also examine the incremental cost of the intervention compared to usual care using a regression model to estimate the difference in expected health care costs between groups.

Results: Study start-up is underway and usability testing is scheduled to begin in the fall of 2016.

Conclusions: Given our experience, dedicated industry partners, and related RCT infrastructure, we are confident we can make a lasting contribution to improving the care of seniors who undergo CaVS.
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http://dx.doi.org/10.2196/resprot.5763DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4999307PMC
August 2016

Mobile technology and the digitization of healthcare.

Eur Heart J 2016 May 11;37(18):1428-38. Epub 2016 Feb 11.

The Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, PO Box 1030, New York, NY 10029, USA

The convergence of science and technology in our dynamic digital era has resulted in the development of innovative digital health devices that allow easy and accurate characterization in health and disease. Technological advancements and the miniaturization of diagnostic instruments to modern smartphone-connected and mobile health (mHealth) devices such as the iECG, handheld ultrasound, and lab-on-a-chip technologies have led to increasing enthusiasm for patient care with promises to decrease healthcare costs and to improve outcomes. This 'hype' for mHealth has recently intersected with the 'real world' and is providing important insights into how patients and practitioners are utilizing digital health technologies. It is also raising important questions regarding the evidence supporting widespread device use. In this state-of-the-art review, we assess the current literature of mHealth and aim to provide a framework for the advances in mHealth by understanding the various device, patient, and clinical factors as they relate to digital health from device designs and patient engagement, to clinical workflow and device regulation. We also outline new strategies for generation and analysis of mHealth data at the individual and population-based levels.
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http://dx.doi.org/10.1093/eurheartj/ehv770DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4914890PMC
May 2016

The healthcare utilization and cost of treating patients experiencing inappropriate implantable cardioverter defibrillator shocks: a propensity score study.

Pacing Clin Electrophysiol 2014 Oct 19;37(10):1315-23. Epub 2014 Aug 19.

Division of Cardiology, Section of Arrhythmia Services, Hartford Hospital, Hartford, Connecticut; Scripps Health, Scripps Translational Sciences Institute, La Jolla, California.

Background: Inappropriate shocks (IASs) from implantable cardioverter defibrillators (ICDs) are associated with decreased quality of life, but whether they increase healthcare utilization and treatment costs is unknown. We sought to determine the impact of IASs on subsequent healthcare utilization and treatment costs.

Methods: We conducted a case-control analysis of ICD patients at a single institution from 1997 to 2010 and who had ≥12 months of post-ICD implant follow-up. Cases included all patients experiencing an IAS during the first 12 months after implantation. Eligible control patients did not receive a shock of any kind during the 12 months after implantation. Propensity scores based on 36 covariates (area under curve = 0.78) were used to match cases to controls. We compared the rate (occurrences/person year [PY]) of healthcare utilization immediately following IAS to the end of the 12-month follow-up period to the rate in the no-shock group over 12 months of follow-up. We also compared 12-month postimplant treatment (outpatient clinic, emergency room, and hospitalization) costs in both groups.

Results: A total of 76 patients experiencing ≥1 IAS during the first 12 months after implant (contributing 48 PYs) were matched to 76 no-shock patients (contributing 76 PYs). Cardiovascular (CV)-related clinic visit and hospitalization rates were increased following an IAS compared to those not receiving a shock (4.0 vs 3.3 and 0.7 vs 0.5, respectively, P = 0.02 for both). CV-related emergency room visitation (0.15 vs 0.08) rates were also numerically higher following an IAS, but did not reach statistical significance (P = 0.26). Patients experiencing an IAS accrued greater treatment costs during the 12 months postimplant compared to no-shock patients ($13,973 ± $46,345 vs $6,790 ± $19,091, P = 0.001).

Conclusion: Recipients of IAS utilize the healthcare system more frequently following an IAS than patients not experiencing a shock. This increased utilization results in higher costs of treating IAS patients during the 12 months postimplant.
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http://dx.doi.org/10.1111/pace.12465DOI Listing
October 2014

Prognostic impact of thyroid stimulating hormone levels in patients with cardiomyopathy.

Conn Med 2013 Aug;77(7):409-15

Hartford Hospital, Hartford, USA.

Background: Thyroid stimulating hormone (TSH) abnormalities have been associated with various cardiac arrhythmias. Effect of TSH abnormalities on mortality and implantable cardioverter defibrillators (ICD) behavior in patients with cardiomyopathy has not been investigated.

Methods: Our ICD database includes 1,445 patients between December 1997 and January 2008. TSH levels using the ultra sensitive assay were available in 371 patients. Patients were classified based on TSH levels as: High TSH (N = 102, TSH > 5) and Low TSH (N = 26, TSH < 0.4). TSH groups were compared for mortality, appropriate and inappropriate ICD therapies.

Results: A high or low TSH was an independent predictor of all-cause mortality: Hazard ratio (HR) 1.46 (95% CI 1.03-2.08), P = 0.033 and HR 1.76 (95% confidence interval 1.02-3.03), P = 0.043 respectively. TSH abnormalities were not associated with an increased incidence in appropriate or inappropriate ICD therapy.

Conclusion: A low or high TSH was associated with a higher mortality; however, neither were associated with appropriate or inappropriate ICD therapy after multivariate analysis. Univariate analysis demonstrated an association of high TSH and appropriate ICD therapy. However, multivariate analysis did not show this association. Therefore, we are concluding that TSH levels are predictors of all-cause mortality but not ICD therapy.
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August 2013

The prognostic impact of pre-implantation hyponatremia on morbidity and mortality among patients with left ventricular dysfunction and implantable cardioverter-defibrillators.

Europace 2014 Jan 16;16(1):47-54. Epub 2013 Aug 16.

Division of Cardiology, Section of Heart Rhythm Management and the Evidence Based Practice Center, Hartford Hospital, University of Connecticut School of Medicine, 80 Seymour Street, Hartford, CT 06102-5037, USA.

Aims: Hyponatremia is commonly observed among patients with left ventricular (LV) dysfunction and is a marker for adverse outcomes. We aimed to determine the prognostic significance of pre-implant hyponatremia on the outcomes of death, acute decompensated heart failure (ADHF) and appropriate implantable cardioverter-defibrillator (ICD) therapy for ventricular arrhythmias among patients with ICDs.

Methods And Results: The study population consisted of patients with an ejection fraction ≤40% undergoing ICD implantation (n = 911) for the primary or secondary prevention of sudden cardiac death from 1997 to 2007. The predictive value of the severity of pre-implantation hyponatremia stratified into mild hyponatremia (n = 268, sodium 134-136 mmol/L), moderate hyponatremia (n = 105, sodium 131-133 mmol/L), and severe hyponatremia (n = 31, sodium ≤130 mmol/L) on the risk of death, ADHF, and appropriate ICD therapy for ventricular arrhythmias as compared with patients a normal serum sodium (n = 507, sodium ≥ 137 mmol/L), was calculated using multivariable Cox proportional hazards analyses. During a mean follow-up of 775 ± 750 days as the severity of hyponatremia (from a normal sodium to severe hyponatremia) increased an incremental incidence of death (25% to 61%, P < 0.001) and ADHF (11% to 26%, P = 0.004) was observed with a reduced incidence of ICD therapy for ventricular tachycardia/ventricular fibrillation (37-29%, P = 0.037). Compared with the normal sodium cohort, patients with severe hyponatremia demonstrated an increased risk of death [adjusted hazard ratio (AHR) 2.69 (95% confidence interval, CI 1.57-4.59), P = 0.004] and ADHF [AHR 2.98 (95% CI 1.41-6.30), P = 0.004], with a lower probability of appropriate ICD therapy [AHR 0.68 (95% CI 0.27-0.88), P = 0.031].

Conclusion: Hyponatremia is commonly observed among ICD recipients with LV dysfunction. Patients with an increasing severity of hyponatremia are at increased risk of death and HF related morbidity with a reduced incidence of appropriate ICD therapy particularly among patients with severe hyponatremia.
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http://dx.doi.org/10.1093/europace/eut211DOI Listing
January 2014

Evaluation of the Charlson comorbidity index to predict early mortality in implantable cardioverter defibrillator patients.

Ann Noninvasive Electrocardiol 2013 Jul 3;18(4):379-88. Epub 2013 May 3.

Division of Cardiology, Section of Heart Rhythm Management and the Evidence Based Practice Center, Hartford Hospital, Hartford CT, USA.

Background: Current guidelines consider the implantation of an implantable cardioverter defibrillator (ICD) a class III indication in patients with a life expectancy of <1 year. An evaluation of concomitant noncardiac conditions may identify patients whom may not derive benefit with ICD therapy. We sought to evaluate the association of the Charlson comorbidity index (CCI) on the prediction of early mortality (EM), death <1 year after ICD implant.

Methods: The study population consisted of patients (n = 1062) undergoing ICD implantation for the primary or secondary prevention of sudden cardiac death from 1997 to 2007. The predictive value of the CCI on the risk of EM and appropriate shock therapy for ventricular arrhythmias as compared to patients without EM after ICD implant was calculated using multivariable Cox proportional hazards and receiver operator analyses.

Results: Patients experiencing EM (n = 110) demonstrated higher CCI scores (mean 2.8 ± 1.3 vs 1.5 ± 1.2, P < 0.001) as compared to individuals without EM (n = 963). Among patients with a CCI of 0, 1, 2, 3, 4, and ≥5, the incidence of EM increased from 5% to 78%. The CCI was an independent predictor of EM (AHR 1.4 [95% CI 1.2-1.6], P < 0.001, per single score increase). Patients who experienced EM demonstrated a decreased incidence of appropriate ICD therapy when compared to patients without EM (AHR 0.4 [95% CI 0.2-0.7], P = 0.001).

Conclusion: Noncardiac conditions are commonly observed among patients undergoing ICD implantation. Guidelines must incorporate a comprehensive assessment of concomitant comorbidities to minimize the risk of EM and to maximize the survival benefit with ICD therapy.
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http://dx.doi.org/10.1111/anec.12045DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6932026PMC
July 2013

The gender-paradox among patients with implantable cardioverter-defibrillators: a propensity-matched study.

Pacing Clin Electrophysiol 2013 Jul 24;36(7):878-84. Epub 2013 Apr 24.

Division of Cardiology, Section of Heart Rhythm Management, and the Evidence Based Practice Center, Hartford Hospital, Hartford, Connecticut, USA.

Background: Several meta-analyses of the implantable cardioverter-defibrillator (ICD) clinical trials have demonstrated that while men derived a mortality reduction with prophylactic ICD implantation, women did not. These trials also observed that women receive less appropriate ICD shock therapy compared to men. We aimed to investigate this "gender-paradox" among a heterogeneous community cohort of patients receiving ICDs.

Methods: We identified 1,445 consecutive patients undergoing ICD implantation from 1997 to 2007. The study population consisted of 582 patients, of whom 291 were women who could be propensity matched to 291 men, based on age, ejection fraction, implantation indication (primary or secondary), etiology of cardiomyopathy (ischemic or nonischemic), and the presence of a cardiac resynchronization therapy-defibrillator (CRT-D) device. The impact of gender difference on the probability of death and appropriate ICD shocks for ventricular arrhythmias was calculated using multivariable Cox proportional hazards analyses.

Results: During a mean follow-up of 909 ± 901 days, compared to men, women demonstrated a similar risk of death (25% vs 25%, adjusted hazard ratio [AHR] 1.05 [95% confidence interval (CI) 0.81-1.35], P = 0.74). In contrast, women demonstrated a decreased probability of appropriate ICD-shock therapy (14% vs 19%, AHR 0.80 [95% CI 0.59-0.88], P = 0.03) compared to men, and among cohorts with a nonischemic cardiomyopathy (10% vs 20%, P < 0.001) and CRT-D devices (7% vs 19%, P = 0.01).

Conclusion: Among a community cohort with ICDs, women have a similar mortality compared to men while experiencing less appropriate ICD therapy. These results support the findings of a lower arrhythmic mortality among women.
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http://dx.doi.org/10.1111/pace.12141DOI Listing
July 2013

Bidirectional ventricular tachycardia due to coronary allograft vasculopathy a unique presentation.

Ann Noninvasive Electrocardiol 2012 Oct 13;17(4):405-8. Epub 2012 Aug 13.

Department of Cardiology and Electrophysiology, Hartford Hospital, University of Connecticut, Hartford, CT, USA.

Bidirectional ventricular tachycardia (BVT) is an uncommon type of polymorphic ventricular tachycardia (PVT) with alternating polarity of the QRS complex most commonly described digitalis toxicity. Recent data has demonstrated the possible molecular basis of this electrocardiographic phenomenon. To our knowledge this is the first reported case of BVT in a patient with orthotopic cardiac transplantation and coronary allograft vasculopathy.
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http://dx.doi.org/10.1111/j.1542-474X.2012.00520.xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6932501PMC
October 2012

Therapeutic hypothermia is associated with improved neurologic outcome and survival in cardiac arrest survivors of non-shockable rhythms.

Resuscitation 2012 Feb 22;83(2):202-7. Epub 2011 Aug 22.

Division of Cardiology, Hartford Hospital, Hartford, CT, United States.

Background: Therapeutic hypothermia improves neurologic outcomes in patients resuscitated from cardiac arrest due to ventricular fibrillation. However, its role in patients with cardiac arrest due to non-shockable rhythms (pulseless electrical activity (PEA) and asystole) is unclear. We hypothesized that therapeutic hypothermia favorably impacts neurologic outcome and survival in patients resuscitated from cardiac arrest due to non-shockable rhythms.

Methods: Retrospectively collected data on consecutive adult patients admitted to Hartford Hospital from 1/1/2004 to 11/1/2010 who survived a cardiac arrest due to PEA or asystole were analyzed. Patients who underwent therapeutic hypothermia (1/1/2007-11/1/2010) formed the hypothermia group while patients admitted prior to the institution of therapeutic hypothermia (1/1/2004-1/1/2007) at Hartford Hospital formed the control group. The primary end-point was measured using the Pittsburgh cerebral performance category (CPC) scale and patients were assessed for a good (CPC 1 and 2) or poor (CPC 3-5) neurological outcome prior to discharge from hospital. A secondary end-point was measured as survival at discharge from hospital.

Results: Of 100 post-cardiac arrest patients included in the study, 15/52 (29%) patients in the hypothermia group had a good neurologic outcome as compared to 5/43 (10%) patients in the control group (P=0.021). On multivariate analysis, the odds ratio for good neurologic outcome and survival at discharge from the hospital with therapeutic hypothermia as compared to control were 4.35 (95% CI 1.10-17.24, P=0.04) and 5.65 (CI 1.66-19.23, P=0.006) respectively.

Conclusion: Therapeutic hypothermia is associated with favorable neurologic outcome and survival in patients resuscitated after cardiac arrest due to non-shockable rhythms.
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http://dx.doi.org/10.1016/j.resuscitation.2011.08.005DOI Listing
February 2012

The prognostic impact of shocks for clinical and induced arrhythmias on morbidity and mortality among patients with implantable cardioverter-defibrillators.

Heart Rhythm 2010 Jun 6;7(6):755-60. Epub 2010 Mar 6.

Department of Cardiology, Evidence Based Practice Center, Hartford Hospital, Hartford, Connecticut 06102-5037, USA.

Background: Recent investigations have demonstrated that the occurrence of implantable cardioverter-defibrillator (ICD) shocks is associated with adverse long-term outcomes. These studies have emphasized that the risk is most reasonably due to arrhythmias rather than to the shock itself. We sought to compare the impact of shock delivery for induced ventricular arrhythmias during implantation defibrillation threshold testing and noninvasive electrophysiology study (NIPS) to clinical shocks on long-term outcomes among patients with ICDs.

Methods: This was a cohort evaluation of 1,372 patients undergoing ICD implantation at a tertiary hospital from December 1997 to January 2007. The probability of all-cause mortality and hospitalization for acute decompensated heart failure (ADHF) was evaluated based upon the type of ICD shock received using multivariable Cox proportional analyses. The four shock types analyzed were implantation shocks only (n = 694), additional NIPS shocks only (n = 319), additional appropriate shocks only (n = 128), or additional inappropriate shocks only (n = 104).

Results: The risk of death (adjusted hazard ratio [AHR] 0.91 [95% confidence interval (CI) 0.69-1.20]; P = .491) or ADHF (AHR 0.71 [95% CI 0.46-1.16]; P = .277) were similar between recipients of NIPS shocks and recipients of implantation shocks. Receiving an appropriate ICD shock increased the risk of death (AHR 2.09 [95% CI 1.38-2.69]; P <.001) and ADHF (AHR 2.40 [95% CI 1.51-3.81]; P <.002) as compared with implantation shocks and also increased the risk of death (AHR 2.61 [95% CI 1.86-3.67]; P <.001) and ADHF (AHR 2.29 [95% CI 1.33-3.97]; P = .003) as compared with NIPS shocks.

Conclusions: ICD shocks delivered during induced ventricular arrhythmias at the time of NIPS testing does not increase the risk of death or ADHF as compared with recipients of appropriate ICD shocks. The occurrence of spontaneous arrhythmias in vulnerable substrates may explain the increased risk.
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http://dx.doi.org/10.1016/j.hrthm.2010.02.039DOI Listing
June 2010

Association between statin therapy and reductions in atrial fibrillation or flutter and inappropriate shock therapy.

Europace 2008 Jul 20;10(7):854-9. Epub 2008 May 20.

Division of Cardiology, Hartford Hospital, 80 Seymour Street, Hartford, CT 06102-5037, USA.

Aims: In patients without implantable cardioverter defibrillators (ICDs), statins have been shown to reduce the incidence of atrial fibrillation and atrial flutter (AF/AFL). We sought to determine if statin therapy could reduce the occurrence of AF/AFL with rapid ventricular rates with and without inappropriate shock therapy among a large heterogeneous ICD cohort.

Methods And Results: We prospectively followed 1445 consecutive patients receiving an ICD for the primary (n = 833) or secondary (n = 612) prevention from December 1997 through January 2007. Outcome measures include incidence of AF/AFL that initiated ICD therapy or was detected during ICD interrogation. Cox hazard regression analyses were conducted to determine the predictors of AF/AFL with and without inappropriate shock delivery and did not include inappropriate shocks resulting from lead dysfunction or other exogenous factors. Patients in this study (n = 1445) were followed over a mean follow-up period of (mean +/- SD) 874 +/- 805 days. There were 563 episodes of AF/AFL detected, with 200 episodes resulting in inappropriate shock therapy. Overall, 745 patients received statin therapy and 700 did not. The use of statin therapy was associated with an adjusted hazard ratio of 0.472 [95% confidence interval (CI), 0.349-0.638, P < 0.001] for the development of AF/AFL with shock therapy and 0.613 (95% CI, 0.496-0.758, P < 0.001) without shock therapy when compared with the group without statin use.

Conclusion: Among a cohort with ICDs at high risk for cardiac arrhythmias, statin therapy was associated with a reduction in AF/AFL tachyarrhythmia detection and inappropriate shock therapy.
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http://dx.doi.org/10.1093/europace/eun128DOI Listing
July 2008

Association between statin use and mortality in patients with implantable cardioverter-defibrillators and left ventricular systolic dysfunction.

Heart Rhythm 2008 Apr 27;5(4):507-10. Epub 2007 Dec 27.

Division of Cardiology, Hartford Hospital, and University of Connecticut Schools of Pharmacy and Medicine, Storrs and Farmington, Connecticut 06102-5037, USA.

Background: A few previous nested cohort trials have evaluated the use of statins on survival and the occurrence of ventricular tachycardia or fibrillation (VT/VF). While the studies generally agreed on the survival effects, they disagreed on the magnitude of the mortality benefit and on the effect on VT/VF.

Objective: The purpose of this study was to determine in a large, long-term follow-up cohort whether statin therapy could reduce mortality and the occurrence of VT/VF in a mixed population receiving an implantable cardioverter-defibrillator (ICD) for primary or secondary prevention and either ischemic or nonischemic cardiomyopathy.

Methods: Cohort evaluation of all patients undergoing implantation of an ICD with a left ventricular ejection fraction <40% at an urban U.S. teaching hospital from December 1997 through January 2007. Multivariable analysis of predictors of mortality and VT/VF were conducted.

Results: There were 314 deaths among the 1204 patients (26.1%). The use of statin therapy (n = 642) was associated with an adjusted hazard ratio of 0.67 (95% confidence interval [CI] 0.53-0.85; P<.001) for mortality as compared with the no-statin group (n = 562). The use of statin therapy was not associated with a reduction in the adjusted hazard ratio for VT/VF (0.85; 95% CI 0.68-1.06; P = .14).

Conclusions: Statin therapy is associated with a reduction in overall mortality in patients with ischemic or nonischemic cardiomyopathy with an ICD implanted for either primary or secondary prevention. The magnitude of survival benefit might have been underestimated given our inability to use statin as a time-dependent covariate.
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http://dx.doi.org/10.1016/j.hrthm.2007.12.023DOI Listing
April 2008