Results from the ABYSS trial surprised many at ESC 2024, finding that patients who continue beta-blocker therapy after heart attacks have better long-term outcomes than patients who stop taking the drugs, and they don’t experience the quality of life downsides that some might expect.
- Roughly 2M people in the United States and Europe have an acute MI every year, often followed by beta-blocker prescriptions.
- Due to a lack of consensus on the optimal duration of beta-blocker therapy, these drugs are often prescribed for life, making them among the world’s most prolific medications.
In the ABYSS trial of 3,698 post-MI patients (LVEF ≥40%) who were already on beta-blockers, researchers randomly assigned participants to either continue or stop taking the medication.
After a median of 3 years the patients who continued beta-blockers had a 2.8% lower risk of experiencing a composite primary endpoint (21.1% vs. 23.8%; death, nonfatal MI, nonfatal stroke, or CV hospitalization), giving beta-blocker interruption a 1.16 hazard ratio.
- However, the continuation group’s lower primary endpoint risks were almost completely driven by its lower rate of cardiovascular hospitalizations (16.6% vs. 18.9%).
- In fact, the two groups had nearly identical rates of all-cause death (4% vs. 4.1%), MI (2.4% vs. 2.5%), and stroke (1% vs. 1%).
Very notable given the motivations for stopping beta-blockers, the continuation and interruption groups also had similar quality of life scores, despite hopes that discontinuing the medication might reduce side effects and enhance day-to-day wellbeing.
These ABYSS results add new fuel to the debate over long-term beta-blocker use…
- They seem to contradict the 2023 U.S. Chronic Coronary Disease guidelines that no longer recommend beta-blocker therapy beyond one year after MI.
- They also seem to contradict the recent REDUCE-AMI trial that found long-term beta-blocker usage didn’t reduce the composite of deaths or MIs (even though the new ABYSS trial also didn’t show meaningful reductions in MI or deaths).
Overall, these conflicting results and guidelines seem to support the new 2024 ESC guidelines, which note that “the duration of beta-blocker therapy, in the long run, is a matter of debate,” and suggest that more research is needed.
The Takeaway
While the appropriate length of beta-blocker treatment after MI remains an open question, the ABYSS trial serves as one key vote in favor of continuing long-term beta-blocker treatment in post-MI patients. However, it will take more conclusive results to know for sure.
