Heart attack patients see no benefits from stopping long-term beta-blocker therapy
Interrupting long-term beta-blocker treatment in patients with a history of myocardial infarction (MI) is not associated with improved outcomes, according to new findings published in The New England Journal of Medicine and presented at European Society of Cardiology (ESC) Congress 2024 in London.[1]
In fact, the study’s authors found that this strategy—which has gained considerable momentum in recent years—was not even noninferior to a strategy of continued beta-blocker therapy.
The ABYSS clinical trial evaluated data from more than 3,500 patients receiving long-term treatment with beta-blocker therapy following an MI. The mean patient age was 63.5 years old, just 17.2% were women and the two groups were associated with similar clinical characteristics While 1,846 patients underwent post-MI treatment that included interrupted beta-blocker therapy, another 1,852 patients continued beta-blocker therapy with no interruption. The most commonly prescribed beta-blockers at baseline were bisoprolol (71.5%), acebutolol (10.8%), atenolol (8.7%) and nebivolol (5.9%). A handful of other medication options were prescribed in approximately 1% or less of the patient population.
Patients were followed for a median of 3 years, and more than 200 patients did crossover from one treatment strategy to the other due to recommendations from their care team.
Overall, the study’s primary outcome—the composite of death, nonfatal MI, nonfatal stroke, or hospitalization for any other cardiovascular reason—was seen in 23.8% of patients in the interruption group and 21.1% of patients in the continuation group. Rates of death (4.1% vs. 4%), repeat nonfatal MI (2.5% vs. 2.4%), nonfatal stroke (1% vs. 1%) and hospitalization for cardiovascular reasons (18.9% vs. 16.6%) between the interruption and continuation groups were also comparable. In addition, quality of life as measured by European Quality of Life–5 Dimensions questionnaires did not reveal a noteworthy difference between the two treatment options.
These relatively slight differences, the team noted, did not fit the criteria for proving noninferiority.
“Improvements in MI management and data from observational studies have led physicians to question whether continuing beta-blockers after 1 year post-MI is needed since unnecessary treatment may result in side effects,” principal investigator Johanne Silvain, MD, PhD, of Sorbonne University in Paris, said in a European Society of Cardiology statement. “We conducted the ABYSS trial to provide conclusive randomized data on the effects of beta-blocker interruption vs. continuation on cardiovascular events and quality of life, but we were unable to show safety preservation in terms of clinical events nor any benefit on quality of life with beta-blocker interruption.”
Silvain et al. added that these findings may make one question why some modern guidelines no longer recommend long-term beta-blocker therapy in MI patients. However, they emphasized that these data tell just part of the story. Additional ongoing trials exploring the use of beta-blockers in this patient population should help provide better answers.
Michael has more than 18 years of experience as a professional writer and editor. He has written at length about cardiology, radiology, artificial intelligence and other key healthcare topics.