Antianginal Efficacy of Carvedilol, a New β-Blocker with Vasodilating Action

Abstract

To evaluate the antianginal efficacy of carvedilol, a beta-blocker with vasodilating activity, we performed a randomized double-blind placebo-controlled study of two single doses of carvedilol. Twelve patients (eight males, four females, mean age 57 years) with stable effort angina and a positive exercise ECG with angina underwent treadmill exercise testing 2 h after either placebo, or carvedilol 25 or 50 mg. Both doses of carvedilol reduced resting heart rate but only the 50 mg dose reduced resting blood pressure. Exercise time and time to angina increased by 24% and 35%, respectively, after carvedilol, and ST depression at both maximal and submaximal work levels was reduced. The time to 1 mm ST depression was increased by carvedilol but the heart rate at 1 mm ST depression and maximum ST/heart rate slope were unchanged. Maximum heart rate, systolic pressure, and rate-pressure product were significantly reduced by carvedilol. The 50 mg dose was significantly better than 25 mg in prolonging exercise time and reducing subjective and objective measurements of ischemia, and this was related to significantly greater hemodynamic effects. Carvedilol appears to be effective in preventing or reducing effort angina due to reduced myocardial oxygen demand, and it exhibits an important dose-response effect.