Setbacks Identified After Stopping Beta-Blockers

The REDUCE-AMI Trial

The ABYSS results appear at first to differ from results from the recent REDUCE-AMI trial, which failed to show the superiority of beta-blocker therapy, compared with no beta-blocker therapy, in acute MI patients with preserved ejection fraction.

But the REDUCE-AMI primary endpoint was a composite of death from any cause or new myocardial infarction; it did not include cardiovascular hospitalization, which was the main driver of the difference in outcomes in the ABYSS study, Dr. Sylvain pointed out.

“We showed an increase in coronary cases of hospitalization with stopping beta-blockers, and you have to remember that beta-blockers were developed to reduce coronary disease,” he said.
 

‘Slightly Inconclusive’

Jane Armitage, MBBS, University of Oxford, England, the ABYSS discussant for the ESC HOTLINE session, pointed out some limitations of the study, which led her to report that the result was “slightly inconclusive.” 

The open-label design may have allowed some bias regarding the cardiovascular hospitalization endpoint, she said.

“The decision whether to admit a patient to [the] hospital is somewhat subjective and could be influenced by a physician’s knowledge of treatment allocation. That is why, ideally, we prefer blinded trials. I think there are questions there,” she explained.

She also questioned whether the non-inferiority margin could have been increased, given the higher-than-expected event rate.

More data on this issue will come from several trials that are currently ongoing, Dr. Armitage said.

The ABYSS and REDUCE-AMI trials together suggest that it is safe, with respect to serious cardiac events, to stop beta-blocker treatment in MI patients with preserved ejection fraction, writes Tomas Jernberg, MD, PhD, from the Karolinska Institute in Stockholm, Sweden, in an accompanying editorial.

However, “because of the anti-ischemic effects of beta-blockers, an interruption may increase the risk of recurrent angina and the need for rehospitalization,” he adds.

“It is prudent to wait for the results of additional ongoing trials of beta-blockers involving patients with MI and a preserved left ventricular ejection fraction before definitively updating guidelines,” Dr. Jernberg concludes.

The ABYSS trial was funded by the French Ministry of Health and the ACTION Study Group. Dr. Sylvain, Dr. Armitage, and Dr. Jernberg report no relevant financial relationships.

A version of this article appeared on Medscape.com.