Little is known about the dosing, tolerability, and impact of beta-blockers in nontrial participants. This study was conducted to evaluate the use and outcomes of beta-blockers in a tertiary care heart failure clinic.
Analysis of prospectively collected data from a cohort of 1041 patients with heart failure seen at the University of Alberta Heart Function Clinic, Edmonton, from September 1, 1989, through July 1, 2001, with objective measurement of ejection fraction at baseline and prospective collection of data at all subsequent clinic visits.
Median age at baseline was 69 years; 65% were male; 75% had systolic dysfunction; mean ejection fraction was 33%; and 51% had New York Heart Association class III or IV symptoms. Median duration of follow-up was 32 months (interquartile range, 13-62 months). Overall, 46% of patients received beta-blockers, but only 18% of these were ultimately prescribed the dosages achieved in the trials (mean maximum dosages achieved, 27 mg/d for carvedilol and 81 mg/d for metoprolol tartrate). Of those patients prescribed beta-blockers, 74% continued to receive them during follow-up. Blood pressure, heart rate, and failure symptomatology did not change appreciably before and after beta-blockers were prescribed, or during the upward titration of the dosage. Although our patients were prescribed lower dosages than those used in trials, Cox multivariate regression revealed that beta-blockers were associated with improved survival, even after adjusting for potential confounders including New York Heart Association class, year of prescription, and concomitant medication use (relative risk, 0.63; 95% confidence interval, 0.50-0.81).
The benefits of beta-blockers seen in randomized trials extend to nontrial participants treated in a tertiary care clinic specializing in heart failure. In our cohort of elderly patients with multiple comorbidities, beta-blockers were well tolerated.