title: Population-based analysis of class effect of β blockers in heart failure.
abstract: The long-term use of β blockers has been shown to improve the outcomes of patients with heart failure (HF). However, it is still disputed whether this is a class effect, and, specifically, whether carvedilol or bisoprolol are superior to metoprolol. The present study was a comparative effectiveness study of β blockers for patients with HF in a population-based setting. We conducted an observational cohort study using the Quebec administrative databases to identify patients with HF who were prescribed a β blocker after the diagnosis of HF. We used descriptive statistics to characterize the patients by the type of β blocker prescribed at discharge. The unadjusted mortality for users of each β blocker was calculated using Kaplan-Meier curves and compared using the log-rank test. To account for differences in follow-up and to control for differences among patient characteristics, a multivariate Cox proportional hazards model was used to compare the mortality. Of the 26,787 patients with HF, with a median follow-up of 1.8 years per patient, the crude incidence of death was 47% with metoprolol, 40% with atenolol, 41% with carvedilol, 36% with bisoprolol, and 43% with acebutolol. After controlling for several different covariates, we found that carvedilol (hazard ratio [HR] 1.04, 95% confidence interval [CI] 0.97 to 1.12, p = 0.22) and bisoprolol (HR 0.96, 95% CI 0.91 to 1.01, p = 0.16) were not superior to metoprolol in improving survival. Atenolol (HR 0.82, 95% CI 0.77 to 0.87, p <0.0001) and acebutolol (HR 0.86, 95% CI 0.78 to 0.95, p = 0.004) were superior to metoprolol. In conclusion, we did not find evidence of a class effect for β blockers in patients with HF.
authors.affiliation: Department of Medicine, McGill University, Montreal, Quebec, Canada.
authors.forename: Darius Lucian
authors.initials: DL
authors.lastname: Lazarus
authors.forename: Cynthia Anne
authors.initials: CA
authors.lastname: Jackevicius
authors.forename: Hassan
authors.initials: H
authors.lastname: Behlouli
authors.forename: Helen
authors.initials: H
authors.lastname: Johansen
authors.forename: Louise
authors.initials: L
authors.lastname: Pilote
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000188:drug therapy* / Q000401:mortality; D006801:Humans; D008297:Male; D011159:Population Surveillance / Q000379:methods*; D011792:Quebec / Q000453:epidemiology; D012189:Retrospective Studies; D015996:Survival Rate / Q000639:trends; D016896:Treatment Outcome
chemical_list: D000319:Adrenergic beta-Antagonists