A Comparison of the Two β-Blockers Carvedilol and Atenolol on Left Ventricular Ejection Fraction and Clinical Endpoints after Myocardial Infarction

BACKGROUND: beta-Blockers have been found to reduce mortality and morbidity in postmyocardial infarction patients. However, it is not fully understood whether all beta-blockers have similar favourable cardiovascular effects. The aim of this study was to compare the effects of carvedilol and atenolol on global and regional left ventricular ejection fraction (LVEF) and on predefined cardiovascular endpoints. METHODS: In a single-centre, randomized, open, endpoint-blinded, parallel group study, 232 patients with acute myocardial infarction were randomized to treatment with carvedilol or atenolol. LVEF was measured by gated blood pool scintigraphy during the first week and after 12 months. The treatment was given orally within 24 h. The mean dose was 36.2 and 72.1 mg in the carvedilol and atenolol groups, respectively. RESULTS: No significant difference was found between the two study groups in the mean global and regional LVEF. There tended to be fewer first serious cardiovascular events in the carvedilol compared with the atenolol group (RR = 0.83, 95% CI 0.56-1.23, p = 0.39). Cold hands and feet were observed less frequently in the carvedilol group (20 vs. 33%, p = 0.025). CONCLUSION: In patients following an acute myocardial infarction, no difference in either global or regional LVEF was observed between baseline and 12 months when treatment with carvedilol was compared with atenolol.