Carvedilol or sustained-release metoprolol for congestive heart failure: A comparative effectiveness analysis

Background: Relative effectiveness of carvedilol and metoprolol succinate has never been compared in patients with heart failure (HF). Methods and Results: From January 1998 to December 2008, 3,716 consecutive patients with ejection fraction (EF) ≤40%, initiated and maintained on carvedilol or metoprolol succinate, were enrolled and followed until June 2010. The primary end point was all-cause mortality, and the secondary end points were readmissions from HF and follow up EFs at 1, 3, and 5 years. HF etiology (ischemic or nonischemic) was a significant effect modifier, and separate analysis was performed for these subcohorts. Compared with those on carvedilol, patients on metoprolol succinate were less likely to experience mortality in the ischemic HF cohort (adjusted hazard ratio [aHR] 0.54, 95% confidence interval [CI] 0.43-0.66) but were more likely to die in the nonischemic HF cohort (aHR 1.18, 95% CI 1.10-1.28). Follow-up EF was similar by type of beta-blocker used in both ischemic and nonischemic HF cohorts. Furthermore, no significant difference was noted in the incidence of HF hospitalizations by beta-blocker type used in both ischemic and nonischemic HF cohorts. Conclusions: Metoprolol succinate was associated with an improved survival in patients with ischemic HF, and carvedilol was associated with an improved survival in patients with nonischemic HF.