179 research outputs found

    Serum markers of deranged myocardial collagen turnover: their relation to malignant ventricular arrhythmias in cardioverter-defibrillator recipients with heart failure

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    BACKGROUND: Pathologic collagen remodeling has been involved in the occurrence of ventricular arrhythmias and sudden cardiac death in heart failure. The aim of the study was to investigate the relationship between malignant ventricular arrhythmias and cardiac collagen turnover indexes, expressing specific types of derangement in collagen physiology, in stable patients with an implantable cardioverter-defibrillator (ICD). METHODS: Seventy-four patients with an ICD and heart failure were studied. They had coronary artery disease (n = 42) or dilated cardiomyopathy, New York Heart Association classes I and II, and left ventricular ejection fraction 29% +/- 1%. An ICD had been implanted for secondary (n = 36) or primary prevention of sudden cardiac death. We assessed (1) markers of collagen types I and III synthesis and their ratio: procollagen type I carboxyterminal peptide (PICP), procollagen type III aminoterminal peptide (PIIINP), and PICP/PIIINP; (2) markers of collagen degradation, degradation inhibition, and their ratio: matrix metalloproteinase 9 (MMP-9), tissue inhibitor of matrix metalloproteinase (TIMP) 1 (TIMP-1), and MMP-9/TIMP-1. Patients were prospectively followed up for 1 year. The number of episodes necessitating appropriate interventions for ventricular tachyarrhythmias (>170 beat/min) was related to the assessed parameters. RESULTS: Multivariate analysis revealed a significant relation between the number of tachyarrhythmic episodes and MMP-9/TIMP-1 (P = .007), PICP/PIIINP (P = .007), and ejection fraction (P = .04). No other significant relation was observed between arrhythmias and the remaining parameters. CONCLUSION: In heart failure, biochemical markers indicative of a deranged equilirium in myocardial collagen deposition/degradation and collagen I/III synthesis are related to ventricular arrhythmogenesis. Further studies are needed to investigate their predictive ability

    Spironolactone improves endothelial and cardiac autonomic function in non heart failure hemodialysis patients

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    OBJECTIVES: Hemodialysis patients have a cardiovascular mortality rate of 20-40 times that of the general population. Aldosterone inhibition by spironolactone has exerted beneficial, prognostically significant cardiovascular effects in patients with heart failure maintained on hemodialysis or peritoneal dialysis. Our aim was to investigate spironolactone\u27s effect in non heart failure hemodialysis patients. METHODS: Fourteen stable chronic hemodialysis patients (nine men), 59.5 +/- 3.1 years of age were evaluated in a sequential, fixed-dose, placebo-controlled study. Heart failure was diagnosed on the basis of signs and symptoms of heart failure or left ventricular ejection fraction less than 50%. Following an initial 4-month period of placebo administration after each dialysis, patients received spironolactone (25 mg thrice weekly after dialysis) for the next 4 months. Data were recorded at baseline, at the end of placebo administration, and at the end of spironolactone treatment and included endothelial function by forearm reactive hyperemia during venous occlusion plethysmography, cardiac autonomic status by heart rate variability in the time and frequency domain, blood pressure response, and echocardiographic and laboratory data. RESULTS: Placebo induced no changes in the aforementioned parameters. Following spironolactone, salutary effects were observed in the extent and duration of reactive hyperemia (P < 0.05 for both), as well as in heart rate variability (P < 0.05) and blood pressure control (P < 0.05). No changes occurred in echocardiographically derived left ventricular dimensions or mass. CONCLUSION: Low-dose spironolactone therapy in clinically stable non heart failure hemodialysis patients is associated with favorable effects on cardiovascular parameters known to adversely affect survival, such as endothelial dysfunction and heart rate variability. Spironolactone treatment might benefit long-term cardiovascular outcome of such patients

    Methods for evaluating endothelial function: a position statement from the European Society of Cardiology Working Group on Peripheral Circulation

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    The endothelium holds a pivotal role in cardiovascular health and disease. Assessment of its function was until recently limited to experimental designs due to its location. The advent of novel techniques has facilitated testing on a more detailed basis, with focus on distinct pathways. This review presents available in-vivo and ex-vivo methods for evaluating endothelial function with special focus on more recent ones. The diagnostic modalities covered include assessment of epicardial and microvascular coronary endothelial function, local vasodilation by venous occlusion plethysmography and flow-mediated dilatation, arterial pulse wave analysis and pulse amplitude tonometry, microvascular blood flow by laser Doppler flowmetry, biochemical markers and bioassays, measurement of endothelial-derived microparticles and progenitor cells, and glycocalyx measurements. Insights and practical information on the theoretical basis, methodological aspects, and clinical application in various disease states are discussed. The ability of these methods to detect endothelial dysfunction before overt cardiovascular disease manifests make them attractive clinical tools for prevention and rehabilitation

    A cost-of-illness analysis of β-Thalassaemia major in children in Sri Lanka - experience from a tertiary level teaching hospital

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    Background Sri Lanka has a high prevalence of β-thalassaemia major. Clinical management is complex and long-term and includes regular blood transfusion and iron chelation therapy. The economic burden of β-thalassaemia for the Sri Lankan healthcare system and households is currently unknown. Methods A prevalence-based, cost-of-illness study was conducted on the Thalassaemia Unit, Department of Paediatrics, Kandy Teaching Hospital, Sri Lanka. Data were collected from clinical records, consultations with the head of the blood bank and a consultant paediatrician directly involved with the care of patients, alongside structured interviews with families to gather data on the personal costs incurred such as those for travel. Results Thirty-four children aged 2–17 years with transfusion dependent thalassaemia major and their parent/guardian were included in the study. The total average cost per patient year to the hospital was US2601ofwhichUS 2601 of which US 2092 were direct costs and US509wereoverheadcosts.MeanhouseholdexpenditurewasUS 509 were overhead costs. Mean household expenditure was US 206 per year with food and transport per transfusion (US7.57andUS 7.57 and US 4.26 respectively) being the highest cost items. Nine (26.5%) families experienced catastrophic levels of healthcare expenditure (> 10% of income) in the care of their affected child. The poorest households were the most likely to experience such levels of expenditure. Conclusions β-thalassaemia major poses a significant economic burden on health services and the families of affected children in Sri Lanka. Greater support is needed for the high proportion of families that suffer catastrophic out-of-pocket costs

    Quantitative analysis of left atrial function in asymptomatic patients with b-thalassemia major using real-time three-dimensional echocardiography

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    <p>Abstract</p> <p>Background</p> <p>There is strong evidence that left atrial (LA) size is a prognostic marker in a variety of heart diseases. Recently, real-time three-dimensional echocardiography (RT3DE) has been reported as a useful tool for studying the phasic changes of the left atrial volumes. The aim of this study was to investigate the performance of the left atrium in beta-thalassemic patients with preserved left ventricular ejection fraction (EF) and no iron overload, using RT3DE.</p> <p>Methods</p> <p>Twenty-eight asymptomatic b-thalassemic patients (32.2 ± 4.3 years old, 17 men) who were on iron chelating therapy, as well as 20 age- and sex-matched healthy controls underwent transthoracic RT3DE. The patient group had normal echocardiographic systolic and diastolic indices, while there was no myocardial iron disposition according to MRI. Apical full volume data sets were obtained and LA volumes were measured at 3 time points of the cardiac cycle: (1) maximum volume (LAmax) at end-systole, just before mitral valve opening; (2) minimum volume (LAmin) at end-diastole, just before mitral valve closure; and (3) volume before atrial active contraction (LApreA) obtained from the last frame before mitral valve reopening or at time of the P wave on the surface electrocardiogram. From the derived values, left atrial active and passive emptying volumes, as well as the respective emptying fractions were calculated.</p> <p>Results</p> <p>Left ventricular EF (59.2 ± 2.5% patients vs. 60.1 ± 2.1% controls), E/A, E/E' were similar between the two groups. Differences in the LAmax, LAmin and LApreA between b-thalassemic patients and controls were non-significant, LAmax:(35.5 ± 13.4 vs 31.8 ± 9.8)cm<sup>3</sup>, LAmin:(16.0 ± 6.0 vs. 13.5 ±4.2)cm<sup>3</sup>, and LApreA:(25.4 ± 9.8 vs. 24.3 ± 7.2)cm<sup>3</sup>. However, left atrial active emptying fraction was reduced in the patient group as compared to the healthy population (34.3 ± 16.4% vs. 43.2 ± 11.4%, p < 0.05).</p> <p>Conclusion</p> <p>RT3DE may be a novel technique for the evaluation of LA function in asymptomatic patients with b-Thalassemia Major. Among three-dimensional volumes and indices, left atrial active emptying fraction may be an early index of LA dysfunction in the specific patient population.</p

    On improvement in ejection fraction with iron chelation in thalassemia major and the risk of future heart failure

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    <p>Abstract</p> <p>Background</p> <p>Trials of iron chelator regimens have increased the treatment options for cardiac siderosis in beta-thalassemia major (TM) patients. Treatment effects with improved left ventricular (LV) ejection fraction (EF) have been observed in patients without overt heart failure, but it is unclear whether these changes are clinically meaningful.</p> <p>Methods</p> <p>This retrospective study of a UK database of TM patients modelled the change in EF between serial scans measured by cardiovascular magnetic resonance (CMR) to the relative risk (RR) of future development of heart failure over 1 year. Patients were divided into 2 strata by baseline LVEF of 56-62% (below normal for TM) and 63-70% (lower half of the normal range for TM).</p> <p>Results</p> <p>A total of 315 patients with 754 CMR scans were analyzed. A 1% absolute increase in EF from baseline was associated with a statistically significant reduction in the risk of future development of heart failure for both the lower EF stratum (EF 56-62%, RR 0.818, p < 0.001) and the higher EF stratum (EF 63-70%, RR 0.893 p = 0.001).</p> <p>Conclusion</p> <p>These data show that during treatment with iron chelators for cardiac siderosis, small increases in LVEF in TM patients are associated with a significantly reduced risk of the development of heart failure. Thus the iron chelator induced improvements in LVEF of 2.6% to 3.1% that have been observed in randomized controlled trials, are associated with risk reductions of 25.5% to 46.4% for the development of heart failure over 12 months, which is clinically meaningful. In cardiac iron overload, heart mitochondrial dysfunction and its relief by iron chelation may underlie the changes in LV function.</p
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