Beta-blocker therapy doesn’t reduce all-cause mortality, cardiovascular mortality, cardiovascular hospitalization, or stroke in patients with heart failure who also have atrial fibrillation, Dipak Kotecha, Ph.D., reported at the annual congress of the European Society of Cardiology in Barcelona.
In a meta-analysis that used the "arduous" process of analyzing individual-patient data from all the high-quality randomized controlled trials available, Dr. Kotecha and his associates found no evidence that beta-blockers prevent adverse clinical events in this patient population. "Beta-blockers should no longer be regarded as standard therapy to improve prognosis" in patients with concomitant heart failure (HF) and atrial fibrillation (AF), he said.
In contrast, the drugs are effective and are strongly recommended for patients with HF who are in sinus rhythm, Dr. Kotecha said in a paper presented at the meeting and simultaneously published online Sept. 2 (Lancet 2014 [doi:10.1016/S0140-6736(14)61373-8]).
Heart failure and atrial fibrillation are common disorders, and both are becoming more prevalent. They often coexist, and an estimated 14%-50% of patients who have symptomatic HF also have AF.
At present, both European and American guidelines advise the use of beta-blockers for symptomatic heart failure without regard to AF status, based on trials that predominantly enrolled patients in sinus rhythm. There have been concerns about the drugs’ efficacy in certain subgroups of patients, including those with AF. "Patients with AF are often prescribed beta-blockers for both prognostic benefit in HF and heart-rate control, although there is little and underpowered evidence for efficacy in terms of clinical outcomes," he noted.
Dr. Kotecha and his associates in the Beta-Blockers in Heart Failure Collaborative Group – a multinational organization "formed to provide definitive answers to open questions about HF and beta-blocker therapy" and to provide clinicians with clear guidance – reviewed data from 18,254 study participants who were followed for a mean of 1.5 years, which allowed a robust and adequately powered analysis of this issue. They included "only unconfounded head-to-head trials with recruitment of more than 300 patients and a planned follow-up of more than 6 months."
A total of 3,066 (17%) of the study participants had AF as well as heart failure, and 633 of them died during follow-up. "A consistent benefit of beta-blockers versus placebo was noted for all death or hospital admission outcomes in patients with sinus rhythm, but the differences were not significant in patients with AF," said Dr. Kotecha of the University of Birmingham (England) Centre for Cardiovascular Sciences.
"The substantial benefit identified in patients with sinus rhythm should not be extrapolated to patients with AF," he said.
It is important to note that beta-blockers did appear to be safe, with no increase in mortality or adverse events, compared with placebo. "This should reassure clinicians, particularly for patients with another indication for beta-blockers, such as MI or the need for rate control of rapid AF with ongoing symptoms," he added.
This study was funded by Menarini Farmaceutica Internazionale, and GlaxoSmithKline provided data extraction support. Neither pharmaceutical group had a role in data analysis or manuscript preparation. Dr. Kotecha is supported by the U.K. National Institute for Health Research and reported receiving grants and honoraria from Menarini. His associates reported ties to numerous device and pharmaceutical sources.