Comparative Effectiveness of Different β-Adrenergic Antagonists on Mortality Among Adults With Heart Failure in Clinical Practice

Background: Randomized trials have demonstrated the efficacy of selected beta-blockers in systolic heart failure, but the comparative effectiveness of different beta-blockers in practice is poorly understood. Methods: We compared mortality associated with different beta-blockers following hospitalization for heart failure between 2001 and 2003. Longitudinal exposure to beta-blockers was ascertained from pharmacy databases. Patient characteristics and other medication use were identified from administrative, hospitalization, outpatient, and pharmacy databases. Death was identified from administrative, state mortality, and Social Security Administration databases. Multivariate Cox regression was used to examine the association between different beta-blockers and death. Results: Among 11 326 adults surviving a hospitalization for heart failure, 7976 received beta-blockers (atenolol, 38.5%; metoprololtartrate, 43.2%; carvedilol, 11.6%; and other, 6.7%) during follow-up. The rate (per 100 person-years) of death during the 12 months after discharge varied by exposure and type of beta-blocker (atenolol, 20.1; metoprolol tartrate, 22.8; carvedilol, 17.7; and no beta-blockers, 37.0). After adjustment for confounders and the propensity to receive carvedilol, the risk of death compared with atenolol was higher for metoprolol tartrate (adjusted hazard ratio [HR], 1.16; 95% confidenceinterval [CI], 1.01-1.34) and no beta-blockers (HR, 1.63; 95% CI, 1.44-1.84) but was not significantly different for carvedilol (HR, 1.16; 95% CI, 0.92-1.44). Conclusions: Compared with atenolol, the adjusted risks of death were slightly higher with shorter-acting metoprolol tartrate but did not significantly differ for carvedilol in adults with heart failure. Our results should be interpreted cautiously and they suggest the need for randomized trials within real-world settings comparing a broader spectrum of beta-blockers for heart failure.