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Alam S.R.,University of Edinburgh | Shah A.S.V.,University of Edinburgh | Richards J.,University of Edinburgh | Lang N.N.,University of Edinburgh | And 14 more authors.
Circulation: Cardiovascular Imaging | Year: 2012

Background-Inflammation following acute myocardial infarction (MI) has detrimental effects on reperfusion, myocardial remodelling, and ventricular function. Magnetic resonance imaging using ultrasmall superparamagnetic particles of iron oxide can detect cellular inflammation in tissues, and we therefore explored their role in acute MI in humans. Methods and Results-Sixteen patients with acute ST-segment elevation MI were recruited to undergo 3 sequential magnetic resonance scans within 5 days of admission at baseline, 24 and 48 hours following no infusion (controls; n=6) or intravenous infusion of ultrasmall superparamagnetic particles of iron oxide (n=10; 4 mg/kg). T2*-weighted multigradient-echo sequences were acquired and R2* values were calculated for specific regions of interest. In the control group, R2* values remained constant in all tissues across all scans with excellent repeatability (bias of ?0.208 s?1, coefficient of repeatability of 26.96 s?1; intraclass coefficient 0.989). Consistent with uptake by the reticuloendothelial system, R2* value increased in the liver (84±49.5 to 319±70.0 s?1; P <0.001) but was unchanged in skeletal muscle (54±8.4 to 67.0±9.5 s?1; P>0.05) 24 hours after administration of ultrasmall superparamagnetic particles of iron oxide. In the myocardial infarct, R2* value increased from 41.0±12.0 s?1 (baseline) to 155±45.0 s?1 (P <0.001) and 124±35.0 s?1 (P <0.05) at 24 and 48 hours, respectively. A similar but lower magnitude response was seen in the remote myocardium, where it increased from 39±3.2 s?1 (baseline) to 80±14.9 s?1 (P <0.001) and 67.0±15.7 s?1 (P <0.05) at 24 and 48 hours, respectively. Conclusions-Following acute MI, uptake of ultrasmall superparamagnetic particles of iron oxide occurs with the infarcted and remote myocardium. This technique holds major promise as a potential method for assessing cellular myocardial inflammation and left ventricular remodelling, which may have a range of applications in patients with MI and other inflammatory cardiac conditions. Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01323296. © 2012 American Heart Association, Inc. Source


Jackson C.E.,University of Glasgow | Myles R.C.,University of Glasgow | Tsorlalis I.K.,University of Glasgow | Dalzell J.R.,University of Glasgow | And 8 more authors.
European Journal of Heart Failure | Year: 2012

Aims: Observational studies in selected populations have suggested that microvolt T-wave alternans (MTWA) testing may identify patients with heart failure (HF) at risk of sudden cardiac death. The aims of this study were to investigate the utility of MTWA testing in an unselected population of patients with HF and to evaluate the clinical characteristics associated with the MTWA results. Methods and results: A total of 1003 patients hospitalized with decompensated HF were enrolled. MTWA testing was planned 1 month post-discharge; 648 patients returned for MTWA testing. Mean age was 70.8 ± 10.6 years and 58 were male. Of these patients who returned, 318 (49) were ineligible for MTWA testing due to atrial fibrillation (AF), pacemaker dependency, or physical inability to undertake the test. Of the MTWA tests, 100 (30) were positive, 78 (24) were negative, and 152 (46) were indeterminate; 112/152 indeterminate tests (74) occurred because of failure to achieve target heart rate (HR) due to chronotropic incompetence or physical limitations. There were differences in patient characteristics according to MTWA result. Independent predictors of a negative result included younger age and higher left ventricular ejection fraction (LVEF). Independent predictors of a positive result included higher HR during MTWA testing and lower LVEF. Independent predictors of an indeterminate result included older age and history of previous/paroxysmal AF. Conclusions: Only half of patients with HF are eligible for MTWA testing and the most common result is an indeterminate test. Patients with positive and indeterminate tests have different clinical characteristics. MTWA treadmill testing is not widely applicable in typical HF patients and is unlikely to refine risk stratification for sudden death on a population level. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2012. Source


Borisenko O.,Synergus AB | Wylie G.,Scottish Extracorporeal Life Support Service | Payne J.,Scottish National Advanced Heart Failure Service | Bjessmo S.,Karolinska Institutet | And 3 more authors.
ASAIO Journal | Year: 2014

The aim of the study was to systematically evaluate effect of CentriMag heart pump (Thoratec Corporation) as temporary ventricular assist device (VAD) and part of extracorporeal membrane oxygenation (ECMO) system on outcomes in patients with cardiac or cardiac-respiratory failure. A systematic search was conducted in five databases for the period 2003 to 2012. Fifty-three publications with data for 999 patients, supported with CentriMag, were included. In 72% studies, CentriMag was used as a VAD and in 25% as part of ECMO circuit. Mean duration of VAD support was 25.0 days in precardiotomy group, 10.9 days in postcardiac surgery cardiogenic shock group, 8.8 days in post-transplant graft failure and rejection group, and 16.0 days in post-LVAD placement right ventricular failure group. Survival on support was 82% (95% CI 70-92) for VAD support in precardiotomy cardiogenic shock indication, 63% (95% CI 46-78) in VAD support in postcardiac surgery cardiogenic shock indication, 62% (95% CI 46-76) in VAD support in post-transplant graft rejection or failure indication, and 83% (95% CI 73-92) in VAD support in post-LVAD placement right ventricular failure indication. CentriMag is an effective technology for temporary support of patients with cardiac and cardiorespiratory failure. Copyright © 2014 by the American Society for Artificial Internal. Source


Jackson C.E.,University of Glasgow | Myles R.C.,University of Glasgow | Tsorlalis I.K.,University of Glasgow | Dalzell J.R.,University of Glasgow | And 9 more authors.
European Journal of Heart Failure | Year: 2013

Aims Microvolt T-wave alternans(MTWA) testing identifies beat-to-beat fluctuations in T-wave morphology, which have been linked to ventricular arrhythmias.However, clinical studies have produced conflicting results and data in heart failure (HF) have been limited. The aim of this study was to determine the prevalence and incremental prognostic value of spectral MTWA testing in an unselected cohort of patients recently hospitalized with HF. Methods and results Consecutive admissions with confirmed HFwere recruited, and survivorswere invited to attend 1 month post-discharge for MTWA testing. A total of 648 of 1003 enrolled patients returned forMTWA testing (58% male, mean age 71 years). Forty-nine per cent were ineligible due to AF, pacemaker dependency, or inability to exercise. Of the 330 MTWA test results, 30% were positive, 24% negative, and 46% indeterminate. Overall, 268 deaths occurred during a median follow-up of 3.1 (interquartile range 1.9-3.9) years. Of the ineligible patients, 48% died vs. 35% of eligible patients (P < 0.001). Of those patients with positive, negative, and indeterminate tests, 27, 35, and 40%, respectively, died (P = 0.12). Even when analysed as non-negative (positive/indeterminate) vs. negative, there was still no betweengroup difference in mortality (P =0.95). MTWA results categorized as positive, negative, or indeterminate showed no incremental prognostic value in a multivariable model, which included BNP. Paradoxically, when compared in a binary fashion with a non-negative result, a negative test was an independent predictor of death, as was ineligibility for MTWA testing. Conclusion Spectral MTWA testing was not widely applicable and failed to predict mortality, and so cannot be endorsed as a risk stratification tool in HF. © The Author 2013. Source


Pettit S.J.,Scottish National Advanced Heart Failure Service | Jhund P.S.,University of Glasgow | Hawkins N.M.,Institute of Cardiovascular Medicine and Science | Gardner R.S.,Scottish National Advanced Heart Failure Service | And 3 more authors.
Circulation: Cardiovascular Quality and Outcomes | Year: 2012

Background-The aim of this study was to assess the relationship between the volume of cardiac transplantation procedures performed in a center and the outcome after cardiac transplantation. Methods and Results-PubMed, Embase, and the Cochrane library were searched for articles on the volume-outcome relationship in cardiac transplantation. Ten studies were identified, and all adopted a different approach to data analysis and varied in adjustment for baseline characteristics. The number of patients in each study ranged from 798 to 14 401, and observed 1-year mortality ranged from 12.6% to 34%. There was no association between the continuous variables of center volume and observed mortality. There was a weak association between the continuous variables of center volume and adjusted mortality up to 1 year and a stronger association at 5 years. When centers were grouped in volume categories, low-volume centers had the highest adjusted mortality, intermediate-volume centers had lower adjusted mortality, and high-volume centers had the lowest adjusted mortality but were not significantly better than intermediate-volume centers. Category limits were arbitrary and varied between studies. Conclusions-There is a relationship between center volume and mortality in heart transplantation. The existence of a minimum acceptable center volume or threshold is unproven. However, a level of 10 to 12 heart transplants per year corresponds to the upper limit of low-volume categories that may have relatively higher mortality. It is not known whether outcomes for patients treated in low-volume transplant centers would be improved by reorganizing centers to ensure volumes in excess of 10 to 12 heart transplants per year. © 2012 American Heart Association, Inc. Source

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