Publications by authors named "Vassilis Vassiliou"

29 Publications

  • Page 1 of 1

Contemporary Role of Cardiac Magnetic Resonance in the Management of Patients with Suspected or Known Coronary Artery Disease.

Medicina (Kaunas) 2021 Jun 24;57(7). Epub 2021 Jun 24.

Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich NR4 7UQ, UK.

Cardiac magnetic resonance imaging (CMR) is a useful non-invasive radiation-free imaging modality for the management of patients with coronary artery disease (CAD). CMR cine imaging provides the "gold standard" assessment of ventricular function, late gadolinium enhancement (LGE) provides useful data for the diagnosis and extent of myocardial scar and viability, while stress imaging is an established technique for the detection of myocardial perfusion defects indicating ischemia. Beyond its role in the diagnosis of CAD, CMR allows accurate risk stratification of patients with established CAD. This review aims to summarize the data regarding the role of CMR in the contemporary management of patients with suspected or known coronary artery disease.
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http://dx.doi.org/10.3390/medicina57070649DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8303732PMC
June 2021

Cardiovascular magnetic resonance predictors of heart failure in hypertrophic cardiomyopathy: the role of myocardial replacement fibrosis and the microcirculation.

J Cardiovasc Magn Reson 2021 03 8;23(1):26. Epub 2021 Mar 8.

NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK.

Introduction: Heart failure (HF) in hypertrophic cardiomyopathy (HCM) is associated with high morbidity and mortality. Predictors of HF, in particular the role of myocardial fibrosis and microvascular ischemia remain unclear. We assessed the predictive value of cardiovascular magnetic resonance (CMR) for development of HF in HCM in an observational cohort study.

Methods: Serial patients with HCM underwent CMR, including adenosine first-pass perfusion, left atrial (LA) and left ventricular (LV) volumes indexed to body surface area (i) and late gadolinium enhancement (%LGE- as a % of total myocardial mass). We used a composite endpoint of HF death, cardiac transplantation, and progression to NYHA class III/IV.

Results: A total of 543 patients with HCM underwent CMR, of whom 94 met the composite endpoint at baseline. The remaining 449 patients were followed for a median of 5.6 years. Thirty nine patients (8.7%) reached the composite endpoint of HF death (n = 7), cardiac transplantation (n = 2) and progression to NYHA class III/IV (n = 20). The annual incidence of HF was 2.0 per 100 person-years, 95% CI (1.6-2.6). Age, previous non-sustained ventricular tachycardia, LV end-systolic volume indexed to body surface area (LVESVI), LA volume index ; LV ejection fraction, %LGE and presence of mitral regurgitation were significant univariable predictors of HF, with LVESVI (Hazard ratio (HR) 1.44, 95% confidence interval (95% CI) 1.16-1.78, p = 0.001), %LGE per 10% (HR 1.44, 95%CI 1.14-1.82, p = 0.002) age (HR 1.37, 95% CI 1.06-1.77, p = 0.02) and mitral regurgitation (HR 2.6, p = 0.02) remaining independently predictive on multivariable analysis. The presence or extent of inducible perfusion defect assessed using a visual score did not predict outcome (p = 0.16, p = 0.27 respectively).

Discussion: The annual incidence of HF in a contemporary ambulatory HCM population undergoing CMR is low. Myocardial fibrosis and LVESVI are strongly predictive of future HF, however CMR visual assessment of myocardial perfusion was not.
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http://dx.doi.org/10.1186/s12968-021-00720-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7941878PMC
March 2021

Predictors and Mechanisms of Atrial Fibrillation in Patients With Hypertrophic Cardiomyopathy.

Am J Cardiol 2020 12 17;136:140-148. Epub 2020 Sep 17.

IHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK.

Atrial fibrillation (AF) in hypertrophic cardiomyopathy (HC) is associated with significant symptomatic deterioration, heart failure, and thromboembolic disease. There is a need for better mechanistic insight and improved identification of at risk patients. We used cardiovascular magnetic resonance (CMR) to assess predictors of AF in HC, in particular the role of myocardial fibrosis. Consecutive patients with HC referred for CMR 2003 to 2013 were prospectively enrolled. CMR parameters including left ventricular volumes, presence and percentage of late gadolinium enhancement in the left ventricle (%LGE) and left atrial volume index (LAVi) were measured. Overall, 377 patients were recruited (age 62 ± 14 years, 73% men). Sixty-two patients (16%) developed new-onset AF during a median follow up of 4.5 (interquartile range 2.9 to 6.0) years. Multivariable analysis revealed %LGE (hazard ratio [HR] 1.3 per 10% (confidence interval: 1.0 to 1.5; p = 0.02), LAVi (HR 1.4 per 10 mL/m[1.2 to 1.5; p < 0.001]), age at HC diagnosis, nonsustained ventricular tachycardia and diabetes to be independent predictors of AF. We constructed a simple risk prediction score for future AF based on the multivariable model with a Harrell's C-statistic of 0.73. In conclusion, the extent of ventricular fibrosis and LA volume independently predicted AF in patients with HC. This finding suggests a mechanistic relation between fibrosis and future AF in HC. CMR with quantification of fibrosis has incremental value over LV and LA measurements in risk stratification for AF. A risk prediction score may be used to identify patients at high risk of future AF who may benefit from more intensive rhythm monitoring and a lower threshold for oral anticoagulation.
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http://dx.doi.org/10.1016/j.amjcard.2020.09.006DOI Listing
December 2020

Molecular diagnostics for detecting pyrethroid and abamectin resistance mutations in Tetranychus urticae.

Pestic Biochem Physiol 2017 Jan 21;135:9-14. Epub 2016 Jul 21.

Hellenic Agricultural Organisation - "DEMETER", NAGREF - Institute of Olive Tree, Subtropical crops and Viticulture, Department of Viticulture, Floriculture, Vegetable crops and Plant Protection, Heraklion, Greece. Electronic address:

Avermectin and pyrethroid resistance mutations (the G314D and the G326E in the glutamate gated chloride channels, and the F1538I in the voltage gated sodium channel) have been reported in the spider mite Tetranychus urticae, one of the most devastating pests of protected and open field crops worldwide. We developed three TaqMan molecular diagnostic assays for monitoring the presence and frequency of these mutations in T. urticae field populations. The TaqMan assays were validated against known genotypes and subsequently used to monitor the frequency of the resistance mutations in eleven T. urticae populations from Greece and Cyprus, with variable history of avermectin and pyrethroids applications. The frequency of the F1538I pyrethroid resistance mutation largely varied among samples, with highest frequencies (75%-97%) detected in four populations derived from protected and open field crops from Crete and Peloponnesus, low frequencies in three populations (2.5%-11%) from Attiki, Cyprus and Crete and not detected in four populations from Crete, Peloponnesus and Cyprus. The frequency of the abamectin resistance mutations G314D and G326E also varied across populations (from 0 to 100%), showing fixation in two populations (>97.5% for the G314D and 100% for the G326E), originating from rose greenhouses from Greece, low frequencies in three populations (5%-12.5%) also originating from rose greenhouses (Crete, Peloponnesus and Cyprus) and not detected in six populations from protected and open field vegetable crops. The TaqMan diagnostics showed higher resolution in detecting specific alleles in low frequency, compared to massive quantitative sequencing approaches previously employed. They can be used, together with classical bioassays, to support evidence - based insecticide resistance management strategies.
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http://dx.doi.org/10.1016/j.pestbp.2016.07.004DOI Listing
January 2017

Mechanisms of Myocardial Ischemia in Hypertrophic Cardiomyopathy: Insights From Wave Intensity Analysis and Magnetic Resonance.

J Am Coll Cardiol 2016 10;68(15):1651-1660

NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, United Kingdom.

Background: Angina is common in hypertrophic cardiomyopathy (HCM) and is associated with abnormal myocardial perfusion. Wave intensity analysis improves the understanding of the mechanics of myocardial ischemia.

Objectives: Wave intensity analysis was used to describe the mechanisms underlying perfusion abnormalities in patients with HCM.

Methods: Simultaneous pressure and flow were measured in the proximal left anterior descending artery in 33 patients with HCM and 20 control patients at rest and during hyperemia, allowing calculation of wave intensity. Patients also underwent quantitative first-pass perfusion cardiac magnetic resonance to measure myocardial perfusion reserve.

Results: Patients with HCM had a lower coronary flow reserve than control subjects (1.9 ± 0.8 vs. 2.7 ± 0.9; p = 0.01). Coronary hemodynamics in HCM were characterized by a very large backward compression wave during systole (38 ± 11% vs. 21 ± 6%; p < 0.001) and a proportionately smaller backward expansion wave (27% ± 8% vs. 33 ± 6%; p = 0.006) compared with control subjects. Patients with severe left ventricular outflow tract obstruction had a bisferiens pressure waveform resulting in an additional proximally originating deceleration wave during systole. The proportion of waves acting to accelerate coronary flow increased with hyperemia, and the magnitude of change was proportional to the myocardial perfusion reserve (rho = 0.53; p < 0.01).

Conclusions: Coronary flow in patients with HCM is deranged. Distally, compressive deformation of intramyocardial blood vessels during systole results in an abnormally large backward compression wave, whereas proximally, severe left ventricular outflow tract obstruction is associated with an additional deceleration wave. Perfusion abnormalities in HCM are not simply a consequence of supply/demand mismatch or remodeling of the intramyocardial blood vessels; they represent a dynamic interaction with the mechanics of myocardial ischemia that may be amenable to treatment.
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http://dx.doi.org/10.1016/j.jacc.2016.07.751DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5054113PMC
October 2016

Clinical practice guidelines for the management of metastatic colorectal cancer: a consensus statement of the Hellenic Society of Medical Oncologists (HeSMO).

Ann Gastroenterol 2016 Oct-Dec;29(4):390-416. Epub 2016 Jun 3.

Medical Oncology, "Metaxas" Cancer Hospital, Piraeus, Greece (Nikolaos Ziras).

There is discrepancy and failure to adhere to current international guidelines for the management of metastatic colorectal cancer (CRC) in hospitals in Greece and Cyprus. The aim of the present document is to provide a consensus on the multidisciplinary management of metastastic CRC, considering both special characteristics of our Healthcare System and international guidelines. Following discussion and online communication among the members of an executive team chosen by the Hellenic Society of Medical Oncology (HeSMO), a consensus for metastastic CRC disease was developed. Statements were subjected to the Delphi methodology on two voting rounds by invited multidisciplinary international experts on CRC. Statements reaching level of agreement by ≥80% were considered as having achieved large consensus, whereas statements reaching 60-80% moderate consensus. One hundred and nine statements were developed. Ninety experts voted for those statements. The median rate of abstain per statement was 18.5% (range: 0-54%). In the end of the process, all statements achieved a large consensus. The importance of centralization, care by a multidisciplinary team, adherence to guidelines, and personalization is emphasized. R0 resection is the only intervention that may offer substantial improvement in the oncological outcomes.
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http://dx.doi.org/10.20524/aog.2016.0050DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5049546PMC
June 2016

Differential diagnosis of left ventricular hypertrophy: usefulness of multimodality imaging and tissue characterization with cardiac magnetic resonance.

Echocardiography 2016 Nov 10;33(11):1765-1768. Epub 2016 Sep 10.

Cardiovascular MR Unit, Royal Brompton Hospital, London, United Kingdom.

Differential diagnosis of asymmetrical left ventricular hypertrophy may be challenging, particularly in patients with history of hypertension. A middle-aged man underwent an echocardiographic examination during workup for hypertension, which unexpectedly showed significant asymmetrical septal hypertrophy and raised suspicion for hypertrophic cardiomyopathy. Cardiovascular magnetic resonance confirmed the asymmetrical hypertrophy. No myocardial late gadolinium contrast enhancement was seen. However, precontrast T1 mapping revealed a low native myocardial T1 value. This was highly suggestive of Anderson-Fabry disease, which was subsequently proved with very low alpha galactosidase enzyme levels and mutation analysis. The case illustrates clinical usefulness of multimodality imaging and the novel tissue characterization techniques for assessment of left ventricular hypertrophy.
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http://dx.doi.org/10.1111/echo.13367DOI Listing
November 2016

Clinical practice guidelines for the surgical treatment of rectal cancer: a consensus statement of the Hellenic Society of Medical Oncologists (HeSMO).

Ann Gastroenterol 2016 Apr-Jun;29(2):103-26

Medical Oncology, University Hospital of Heraklion, Greece (John Souglakos).

In rectal cancer management, accurate staging by magnetic resonance imaging, neo-adjuvant treatment with the use of radiotherapy, and total mesorectal excision have resulted in remarkable improvement in the oncological outcomes. However, there is substantial discrepancy in the therapeutic approach and failure to adhere to international guidelines among different Greek-Cypriot hospitals. The present guidelines aim to aid the multidisciplinary management of rectal cancer, considering both the local special characteristics of our healthcare system and the international relevant agreements (ESMO, EURECCA). Following background discussion and online communication sessions for feedback among the members of an executive team, a consensus rectal cancer management was obtained. Statements were subjected to the Delphi methodology voting system on two rounds to achieve further consensus by invited multidisciplinary international experts on colorectal cancer. Statements were considered of high, moderate or low consensus if they were voted by ≥80%, 60-80%, or <60%, respectively; those obtaining a low consensus level after both voting rounds were rejected. One hundred and two statements were developed and voted by 100 experts. The mean rate of abstention per statement was 12.5% (range: 2-45%). In the end of the process, all statements achieved a high consensus. Guidelines and algorithms of diagnosis and treatment were proposed. The importance of centralization, care by a multidisciplinary team, adherence to guidelines, and personalization is emphasized.
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http://dx.doi.org/10.20524/aog.2016.0003DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4805730PMC
April 2016

Tuberculous Constrictive Pericarditis.

Res Cardiovasc Med 2015 Nov 7;4(4):e29614. Epub 2015 Sep 7.

Cardiovascular Magnetic Resonance Unit, Royal Brompton Hospital, London, UK.

Introduction: Constrictive pericarditis is characterized by constriction of the heart secondary to pericardial inflammation. Cardiovascular magnetic resonance (CMR) imaging is useful imaging modality for addressing the challenges of confirming this diagnosis. It can be used to exclude other causes of right heart failure, such as pulmonary hypertension or myocardial infarction, determine whether the pericardium is causing constriction and differentiate it from restrictive cardiomyopathy, which also causes impaired cardiac filling.

Case Presentation: A 77-year-old man from a country with high incidence of tuberculosis presented with severe dyspnea. Echocardiography revealed a small left ventricle with normal systolic and mildly impaired diastolic function. Left heart catheterization revealed non-obstructive coronary disease, not felt contributory to the dyspnea. Anatomy imaging with cardiovascular magnetic resonance imaging (CMR) showed global, severely thickened pericardium. Short tau inversion recovery (STIR) sequences for detection of oedema/ inflammation showed increased signal intensity and free breathing sequences confirmed septal flattening on inspiration. Late gadolinium imaging confirmed enhancement in the pericardium, with all findings suggestive of pericardial inflammation and constriction.

Conclusions: CMR with STIR sequences, free breathing sequences and late gadolinium imaging can prove extremely useful for diagnosing constrictive pericarditis.
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http://dx.doi.org/10.5812/cardiovascmed.29614DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4707979PMC
November 2015

Renal denervation for the management of resistant hypertension.

Integr Blood Press Control 2015 3;8:57-69. Epub 2015 Dec 3.

NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK.

Renal sympathetic denervation (RSD) as a therapy for patients with resistant hypertension has attracted great interest. The majority of studies in this field have demonstrated impressive reductions in blood pressure (BP). However, these trials were not randomized or sham-controlled and hence, the findings may have been overinflated due to trial biases. SYMPLICITY HTN-3 was the first randomized controlled trial to use a blinded sham-control and ambulatory BP monitoring. A surprise to many was that this study was neutral. Possible reasons for this neutrality include the fact that RSD may not be effective at lowering BP in man, RSD was not performed adequately due to limited operator experience, patients' adherence with their anti-hypertensive drugs may have changed during the trial period, and perhaps the intervention only works in certain subgroups that are yet to be identified. Future studies seeking to demonstrate efficacy of RSD should be designed as randomized blinded sham-controlled trials. The efficacy of RSD is in doubt, but many feel that its safety has been established through the thousands of patients in whom the procedure has been performed. Over 90% of these data, however, are for the Symplicity™ system and rarely extend beyond 12 months of follow-up. Long-term safety cannot be assumed with RSD and nor should it be assumed that if one catheter system is safe then all are. We hope that in the near future, with the benefit of well-designed clinical trials, the role of renal denervation in the management of hypertension will be established.
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http://dx.doi.org/10.2147/IBPC.S65632DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4675644PMC
December 2015

T1 at 1.5T and 3T compared with conventional T2* at 1.5T for cardiac siderosis.

J Cardiovasc Magn Reson 2015 Nov 24;17:102. Epub 2015 Nov 24.

NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK.

Background: Myocardial black blood (BB) T2* relaxometry at 1.5T provides robust, reproducible and calibrated non-invasive assessment of cardiac iron burden. In vitro data has shown that like T2*, novel native Modified Look-Locker Inversion recovery (MOLLI) T1 shortens with increasing tissue iron. The relative merits of T1 and T2* are largely unexplored. We compared the established 1.5T BB T2* technique against native T1 values at 1.5T and 3T in iron overload patients and in normal volunteers.

Methods: A total of 73 subjects (42 male) were recruited, comprising 20 healthy volunteers (controls) and 53 patients (thalassemia major 22, sickle cell disease 9, hereditary hemochromatosis 9, other iron overload conditions 13). Single mid-ventricular short axis slices were acquired for BB T2* at 1.5T and MOLLI T1 quantification at 1.5T and 3T.

Results: In healthy volunteers, median T1 was 1014 ms (full range 939-1059 ms) at 1.5T and modestly increased to 1165ms (full range 1056-1224 ms) at 3T. All patients with significant cardiac iron overload (1.5T T2* values <20 ms) had T1 values <939 ms at 1.5T, and <1056 ms at 3T. Associations between T2* and T1 were found to be moderate with y =377 · x(0.282) at 1.5T (R(2) = 0.717), and y =406 · x(0.294) at 3T (R(2) = 0.715). Measures of reproducibility of T1 appeared superior to T2*.

Conclusions: T1 mapping at 1.5T and at 3T can identify individuals with significant iron loading as defined by the current gold standard T2* at 1.5T. However, there is significant scatter between results which may reflect measurement error, but it is also possible that T1 interacts with T2*, or is differentially sensitive to aspects of iron chemistry or other biology. Hurdles to clinical implementation of T1 include the lack of calibration against human myocardial iron concentration, no demonstrated relation to cardiac outcomes, and variation in absolute T1 values between scanners, which makes inter-centre comparisons difficult. The relative merits of T1 at 3T versus T2* at 3T require further consideration.
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http://dx.doi.org/10.1186/s12968-015-0207-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4659152PMC
November 2015

Clinical value of cardiovascular magnetic resonance in patients with MR-conditional pacemakers.

Eur Heart J Cardiovasc Imaging 2016 Oct 20;17(10):1178-85. Epub 2015 Nov 20.

NIHR Cardiovascular Biomedical Research Unit, Royal Brompton and Harefield NHS Foundation Trust and Imperial College, Sydney Street, London SW3 6NP, UK.

Aims: Magnetic resonance (MR) conditional pacemakers are increasingly implanted into patients who may need cardiovascular MR (CMR) subsequent to device implantation. We assessed the added value of CMR for diagnosis and management in this population.

Methods And Results: CMR and pacing data from consecutive patients with MR conditional pacemakers were retrospectively reviewed. Images were acquired at 1.5 T (Siemens Magnetom Avanto). The indication for CMR and any resulting change in management was recorded. The quality of CMR was rated by an observer blinded to clinical details, and data on pacemaker and lead parameters were collected pre- and post-CMR. Seventy-two CMR scans on 69 patients performed between 2011 and 2015 were assessed. All scans were completed successfully with no significant change in lead thresholds or pacing parameters. Steady-state free precession (SSFP) cine imaging resulted in a greater frequency of non-diagnostic imaging (22 vs. 1%, P < 0.01) compared with gradient echo sequences (GRE). Right-sided pacemakers were associated with less artefact than left-sided pacemakers. Late gadolinium enhancement imaging was performed in 59 scans with only 2% of segments rated of non-diagnostic quality. The CMR data resulted in a new diagnosis in 27 (38%) of examinations; clinical management was changed in a further 18 (25%).

Conclusions: CMR in patients with MR conditional pacemakers provided diagnostic or management-changing information in the majority (63%) of our cohort. The use of gradient echo cine sequences can reduce rates of non-diagnostic imaging. Right-sided device implantation may be considered in patients likely to require CMR examination.
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http://dx.doi.org/10.1093/ehjci/jev305DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5964714PMC
October 2016

Left ventricular hypertrophy with strain and aortic stenosis.

Circulation 2014 Oct 28;130(18):1607-16. Epub 2014 Aug 28.

From the British Heart Foundation/University Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK (A.S.V.S., C.W.L.C., M.D., T.C.K., S.S., A.C.W., N.A.B., N.L.M., D.E.N., M.R.D.); Department of Cardiovascular Medicine, National Heart Center Singapore, Singapore (C.W.L.C.); Royal Brompton Hospital, London, UK (V.V., S.K.P.); National Heart and Lung Institute, Imperial College, London, UK (V.V., S.K.P.); NHS Lothian, Edinburgh, UK (S.J.C., A.C.W., G.M., N.A.B., N.L.M., D.E.N., M.R.D.); Clinical Research Imaging Centre, University of Edinburgh, Edinburgh, UK (S.S., D.E.N.); and Department of Cardiothoracic Surgery, Royal Infirmary of Edinburgh, Edinburgh, UK (V.Z.).

Background: ECG left ventricular hypertrophy with strain is associated with an adverse prognosis in aortic stenosis. We investigated the mechanisms and outcomes associated with ECG strain.

Methods And Results: One hundred and two patients (age, 70 years [range, 63-75 years]; male, 66%; aortic valve area, 0.9 cm(2) [range, 0.7-1.2 cm(2)]) underwent ECG, echocardiography, and cardiovascular magnetic resonance. They made up the mechanism cohort. Myocardial fibrosis was determined with late gadolinium enhancement (replacement fibrosis) and T1 mapping (diffuse fibrosis). The relationship between ECG strain and cardiovascular magnetic resonance was then assessed in an external validation cohort (n=64). The outcome cohort was made up of 140 patients from the Scottish Aortic Stenosis and Lipid Lowering Trial Impact on Regression (SALTIRE) study and was followed up for 10.6 years (1254 patient-years). Compared with those without left ventricular hypertrophy (n=51) and left ventricular hypertrophy without ECG strain (n=30), patients with ECG strain (n=21) had more severe aortic stenosis, increased left ventricular mass index, more myocardial injury (high-sensitivity plasma cardiac troponin I concentration, 4.3 ng/L [interquartile range, 2.5-7.3 ng/L] versus 7.3 ng/L [interquartile range, 3.2-20.8 ng/L] versus 18.6 ng/L [interquartile range, 9.0-45.2 ng/L], respectively; P<0.001) and increased diffuse fibrosis (extracellular volume fraction, 27.4±2.2% versus 27.2±2.9% versus 30.9±1.9%, respectively; P<0.001). All patients with ECG strain had midwall late gadolinium enhancement (positive and negative predictive values of 100% and 86%, respectively). Indeed, late gadolinium enhancement was independently associated with ECG strain (odds ratio, 1.73; 95% confidence interval, 1.08-2.77; P=0.02), a finding confirmed in the validation cohort. In the outcome cohort, ECG strain was an independent predictor of aortic valve replacement or cardiovascular death (hazard ratio, 2.67; 95% confidence interval, 1.35-5.27; P<0.01).

Conclusion: ECG strain is a specific marker of midwall myocardial fibrosis and predicts adverse clinical outcomes in aortic stenosis.
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http://dx.doi.org/10.1161/CIRCULATIONAHA.114.011085DOI Listing
October 2014

Markers of left ventricular decompensation in aortic stenosis.

Expert Rev Cardiovasc Ther 2014 Jul 28;12(7):901-12. Epub 2014 May 28.

BHF/Centre for Cardiovascular Science, University of Edinburgh, 49 Little France Crescent, Edinburgh, EH16 4SB, UK.

Calcified aortic stenosis is a condition that affects the valve and the myocardium. As the valve narrows, left ventricular hypertrophy occurs initially as an adaptive mechanism to maintain cardiac output. Ultimately, the ventricle decompensates and patients transition towards heart failure and adverse events. Current guidelines recommend aortic valve replacement in patients with severe aortic stenosis and evidence of decompensation based on either symptoms or an impaired ejection fraction <50%. However, symptoms can be subjective and correlate only modestly with the severity of aortic stenosis whilst impaired ejection fraction is an advanced manifestation and often irreversible. In this review, the authors will discuss the pathophysiology of left ventricular hypertrophy and the transition to heart failure. Subsequently, the authors will examine novel biomarkers that may better identify the transition from hypertrophy to heart failure and therefore guide the optimal timing for aortic valve replacement.
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http://dx.doi.org/10.1586/14779072.2014.923307DOI Listing
July 2014

Acaricide resistance in Tetranychus urticae (Acari: Tetranychidae) populations from Cyprus.

J Econ Entomol 2013 Aug;106(4):1848-54

Plant Protection Section, Agricultural Research Institute, P.O. Box 22016, 1516 Nicosia, Cyprus.

Five field and greenhouse populations of the twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), were collected from five different districts across the island of Cyprus, both in field and greenhouse crops, and tested to determine levels of resistance. Standard leaf-disk spray application bioassay procedures were used to determine the LC50s for five chemicals: abamectin, acrinathrin, fenazaquin, pirimiphos methyl, and bifenazate. Selection of these compounds was based on the widespread use by farmers as well as on the frequent control failures against T. urticae reported in the past. Resistance of T. urticae was detected to abamectin, acrinathrin, fenazaquin, and pirimiphos methyl. The resistance ratios were calculated relative to the German susceptible reference strain. The highest resistance ratios at LC50 value were recorded for abamectin in a greenhouse rose population (RR = 3822), followed by a field bean (RR = 1356) and field tomato population (RR = 1320). Significantly high resistance levels were also found for acrinathrin where the highest resistance ratios at LC50 were recorded in a field bean T. urticae population (RR = 903). For fenazaquin, the highest resistance levels were recorded in a field tomato population (RR = 310). Lower resistance levels were found for pirimiphos methyl (13.3 < RR < 77.4) in all populations. Low susceptibility of T. urticae was observed for bifenazate (2.7 < RR < 24.4) in all populations. These results suggest that at least the use of abamectin and acrinathrin should be avoided or minimized for the control of T. urticae populations in indoor and outdoor environments.
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http://dx.doi.org/10.1603/ec12369DOI Listing
August 2013

Kounis syndrome: not to be sneezed at.

Heart 2013 Jan;99(1):68

Department of Cardiology, Papworth Hospital, Papworth Everard, Cambridge CB23 3RE, UK.

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http://dx.doi.org/10.1136/heartjnl-2012-302790DOI Listing
January 2013

Apixaban in atrial fibrillation: does predicted risk matter?

Lancet 2012 Nov 2;380(9855):1718-20. Epub 2012 Oct 2.

Papworth Hospital, Cambridge University Health Partners, Papworth Everard, Cambridge CB23 8RE, UK.

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http://dx.doi.org/10.1016/S0140-6736(12)61673-0DOI Listing
November 2012

One heart, two cardiomyopathies.

BMJ Case Rep 2012 Jun 5;2012. Epub 2012 Jun 5.

Department of Cardiology, Papworth Hospital, Cambridge, UK.

A 63-year-old woman with no previous medical problems presented with acute chest pain and an ECG consistent with an acute anterior myocardial infarction. At emergency angiography, she was found to have smooth unobstructed coronary arteries. On invasive left ventriculography, overall poor systolic function was noted with apical hypokinesis and basal hyperkinesis, consistent with Tako-tsubo phenomenon. Echocardiography demonstrated a hypertrophic left ventricle and left ventricular outflow obstruction due to systolic anterior motion of the mitral valve and moderate mitral regurgitation. Following appropriate management, she was discharged 6 days later. An outpatient MRI confirmed normalisation of the left ventricular systolic function; however, there was still significant left ventricular hypertrophy and dynamic obstruction. Although most patients presenting with chest pain and an ECG with ST elevation will have an acute coronary event, our patient had normal coronaries but both Tako-tsubo and hypertrophic cardiomyopathies.
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http://dx.doi.org/10.1136/bcr-03-2012-5968DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4542725PMC
June 2012

Stressed at the dentist? A case of tako-tsubo.

Cardiol J 2012 ;19(2):205-6

Department of Cardiology, Cambridge University Hospitals, Cambridge, UK.

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http://dx.doi.org/10.5603/cj.2012.0037DOI Listing
July 2013

Pacemaker clinics and anticoagulation for atrial fibrillation.

Europace 2012 Sep 1;14(9):1375; author reply 1375-6. Epub 2012 Mar 1.

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http://dx.doi.org/10.1093/europace/eus037DOI Listing
September 2012

Anti-tumour-necrosis-factor-alpha agents and the heart: beyond left ventricular systolic dysfunction?

N Z Med J 2011 Sep 23;124(1343):76-8. Epub 2011 Sep 23.

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September 2011

Double-dose clopidogrel in patients undergoing PCI for ACS.

Lancet 2011 Jan;377(9762):297; author reply 298

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http://dx.doi.org/10.1016/S0140-6736(11)60088-3DOI Listing
January 2011

What will the 'creatinine kinase' be in 2016?

Eur J Cardiothorac Surg 2007 Feb 15;31(2):333; author reply 333. Epub 2006 Dec 15.

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http://dx.doi.org/10.1016/j.ejcts.2006.11.020DOI Listing
February 2007

Insertion/deletion polymorphism of the angiotensin I-converting enzyme gene and arterial oxygen saturation at high altitude.

Am J Respir Crit Care Med 2002 Aug;166(3):362-6

UCL Centre for Cardiovascular Genetics, Rayne Institute, St. Bartholomew's and the Royal London MDS, London, UK.

There is a significant genetic influence on arterial oxygen saturation (Sa(O(2))) in high-altitude (HA) residents. It is not known whether this is true of lowlanders ascending to HA. The I allele of the angiotensin-converting enzyme (ACE) gene is associated with low ACE activity and elite endurance performance. An excess of the I allele has also been reported in South American natives living over 3,000 m and among elite HA mountaineers who demonstrate extreme endurance in a hypoxic environment, where maintenance of Sa(O(2)) is crucial to performance. We postulated that the I allele may confer an advantage at HA through genotype-dependent alterations in Sa(O(2)). Rapid ascent (n = 32) and slow ascent groups (n = 40), ascending to approximately 5,000 m over 12.0 and 18.5 days, respectively, had their Sa(O(2)) assessed throughout and compared with their ACE genotype. Resting Sa(O(2)) was independent of the ACE genotype and remained so for the slow ascent group, in whom the fall in Sa(O(2)) with ascent was genotype independent. However, Sa(O(2)) with ascent was significantly associated with the ACE genotype in the rapid ascent group (p = 0.01) with a relatively sustained Sa(O(2)) in the II subjects. These data are the first to report an association of the I allele with the maintenance of Sa(O(2)) at HA.
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http://dx.doi.org/10.1164/rccm.2103060DOI Listing
August 2002

Severity of meningococcal disease in children and the angiotensin-converting enzyme insertion/deletion polymorphism.

Am J Respir Crit Care Med 2002 Apr;165(8):1103-6

Peter Dunn Neonatal Intensive Care Unit and Department of Child Health, University of Bristol, Bristol, United Kingdom.

Critical illness outcome may be causally related to inflammatory response severity. Given that tissue angiotensin-converting-enzyme (ACE) regulates such responses and that the deletion (D) [rather than insertion (I)] variant of the ACE gene is associated with higher tissue ACE levels, DD genotype might be associated with a poorer outcome in a uniform infectious disease state. Illness severity (Pediatric RIsk of Mortality score, the Glasgow Meningococcal Septicaemia Prognostic Score [GMSPS], and clinical course) was recorded for consecutive white patients with meningococcal disease (n = 110, 34 DD genotype, 61 male, aged 49.4 +/- 5.4 months) referred to the Royal Liverpool Children's Hospital, UK. Compared with children with > or = I allele, DD genotype was associated with 14% higher predicted risk of mortality (p = 0.038), higher GMSPS (DD 9.4 +/- 0.5, ID/II 7.7+/- 0.4 [mean +/- SEM], p = 0.013), greater prevalence of inotropic support (76% versus 55%, p = 0.03) and ventilation (82% versus 63%, p = 0.04), and longer Pediatric Intensive Care Unit (PICU) stay (5.8 versus 3.9, p = 0.02). DD genotype frequency was 6% (1 case) for the 18 children who did not require PICU care, 33% for the 84 PICU survivors, and 45% for those who died (p = 0.01). ACE DD is associated with increased illness severity in meningococcal disease.
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http://dx.doi.org/10.1164/ajrccm.165.8.2108089DOI Listing
April 2002
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