Arg389Gly-beta1-adrenergic receptors determine improvement in left ventricular systolic function in nonischemic cardiomyopathy patients with heart failure after chronic treatment with carvedilol.

OBJECTIVE: Administration of the beta-adrenergic receptor blocker carvedilol to patients with chronic heart failure leads to clinically significant benefits, including improvement in left ventricular systolic function in some, but not all, patients. We sought to determine the basis of the variable effect obtained with carvedilol in patients with heart failure. Carvedilol blocks both beta1-adrenergic and beta2-adrenergic receptors, and both receptors exist as polymorphisms. We aimed to determine whether these polymorphisms contribute to variability in response to carvedilol in patients with chronic heart failure. METHODS: We retrospectively and prospectively investigated 135 patients with nonischemic cardiomyopathy and chronic stable heart failure (New York Heart Association class II, III) treated with carvedilol. Baseline echocardiography was obtained before introduction of carvedilol and repeated after stabilization of a maximally tolerated dose of carvedilol (50-100 mg/day) for at least 1 year. Polymerase chain reaction and restriction fragment length polymorphism analysis were used to genotype beta1-adrenergic and beta2-adrenergic receptor polymorphisms. RESULTS: When grouped according to receptor polymorphisms patients were well matched for severity of heart failure, comorbidity and treatment. No significant difference was observed in baseline left ventricular ejection fraction (LVEF) between groups (P>0.05). After 1.5 years of treatment with carvedilol patients with Arg389Arg-beta1-adrenergic receptors had a significantly greater improvement in LVEF compared with Gly389 carriers (Arg389Arg 18.8%; Arg389Gly 9.4%; Gly389Gly 6.0%; P<0.001) whereas there were no differences attributable to other beta1-adrenergic and beta2-adrenergic receptor polymorphisms (P>0.05). CONCLUSION: In patients with nonischemic dilated cardiomyopathy, carvedilol leads to a significantly greater improvement in LVEF in patients with the Arg389Arg-beta1 adrenergic receptor phenotype.

Clinical experience of sirolimus-eluting stents in patients with coronary artery disease at Bangkok Heart Institute.

Drug eluting stents represent one of the fastest growing fields in interventional cardiology today. From a recent study, the sirolimus eluting stent (SES) (CYPHER, Cordis, Johnson & Johnson) appear to demonstrate a remarkable efficacy and safety in preventing restenosis. From the present study, the authors reported clinical experience of SES in 40 consecutive patients with coronary artery disease (CAD) between 25th June and 11th October, 2002. The mean age was 59 +/- 12.16 years (mean +/- SD) and 80 per cent of the patients were male. The majority of the patients had chronic stable angina and most percutaneous coronary interventions were performed by elective procedure (85%). Thirty-five per cent of the patients had single vessel disease and 42.5 per cent of the patients had double vessel disease. The authors successfully implanted 52 (69.3%) SES in 75 target lesions revascularization. Twenty-four (60%) of the patients had more than 1 vessel intervention. Twenty-seven (67.5%) of the patients had complete revascularization by percutaneous coronary intervention (PCI) and only 16 of 27 patients (59.3%) who had complete revascularization with SES. The SES were usually implanted at middle part of the left anterior descending artery (MLAD) (11 lesions), proximal part of the left anterior descending artery (PLAD) (8 lesions), middle part of the right coronary artery (MRCA) (8 lesions) and middle part of the left circumflex artery (MLCX) (6 lesions). The authors had to cover plaque entirely with SES, so SES implantation usually took longer than the bare stent (BS). The authors followed the initial clinical outcome of the patients within 1 month after discharge. Few adverse clinical events were found during 1 month follow-up because SES have a very low rate of restenosis in the short-term so, we have to follow-up the patients over a longer period and will report the clinical outcome in the next study.