[Future perspectives of beta-blockers in chronic heart failure].
ABSTRACT The efficacy of beta-blockers for improving the survival rate of patients with chronic heart failure has been confirmed by results deriving from a series of randomized controlled trials (RCTs) such as MERIT-HF, CIBIS-II, and COPERNICUS. Thus, treatment guidelines recommend that beta-blockers should be used in all patients with heart failure resulting from left ventricular systolic dysfunction who can tolerate with beta-blockers. Despite these guidelines, actual rates of beta-blocker prescription has been lower than expected, and when used, beta-blockers are generally prescribed in doses lower than what has been shown to reduce morbidity and mortality in RCTs. In the MUCHA trial conducted in Japan, the beta-blocker carvedilol decreased the cardiovascular risk for hospitalization in a dose-dependent manner. The 5 mg/day dose achieved a remarkable reduction that was nearly as great as the 20 mg/day dose. Whether this low-dose therapy was sufficient was not fully investigated by the MUCHA trial. Moreover, there is an ethnic difference in the effective dose between patients in Japan and Western countries, which may depend on a difference in beta1-receptor sensitivity. J-CHF trial may suggest that low doses of carvedilol under 2.5 mg/day have a beneficial effect. This trial is a randomized multi-center parallel group dose-comparison study, and with sub-studies such as an analysis of genetic polymorphisms on voluntary participation. This trial may serve as a tailored approach for Japanese physicians in the clinical management of heart failure.