A significant new study conducted in Spain and Italy has raised questions about the effectiveness of beta blockers for patients recovering from a heart attack. These medications, commonly prescribed to slow heart rate and lower blood pressure, did not show clear benefits for patients whose heart function remained intact. The findings, part of the REBOOT trial, were published in the New England Journal of Medicine and presented during the European Society of Cardiology Congress 2025 held in Madrid.
The REBOOT trial involved over 8,400 patients recovering from a heart attack, all of whom had a heart function above 40%. Participants were randomly assigned to either receive beta blockers or not, within two weeks of hospital discharge. Over an average follow-up period of approximately 3.7 years, the study revealed no significant differences in the rates of death from any cause, repeat heart attacks, or hospitalizations for heart failure between the two groups.
A subanalysis of the REBOOT trial, published in the European Heart Journal, focused on the outcomes for about 1,600 women from the original study. The results indicated that beta blockers were linked to an increased risk of death from all causes among these women compared to those who did not take the medication. Conversely, no similar risk was found in male participants. The authors cautioned that these findings should be interpreted with care, as the women in the REBOOT trial tended to be older, sicker, and received less treatment for heart attacks than their male counterparts.
On the same day, results from another clinical trial, BETAMI-DANBLOCK, were also published in the New England Journal of Medicine. This trial, which included more than 5,000 adults diagnosed with a heart attack, demonstrated that those treated with beta blockers experienced fewer non-fatal heart attacks during the 3.5-year study period. However, similar to the REBOOT trial, there were no significant differences in mortality, heart failure, stroke, or other major cardiac events between the beta blocker group and those who did not receive the medication.
Dr. Gregg Fonarow, a professor of cardiovascular medicine at the University of California, Los Angeles, noted that the primary finding of the BETAMI-DANBLOCK study was a reduction in non-fatal heart attacks. However, both studies have limitations. Dr. Steven Pfau from Yale School of Medicine emphasized that the REBOOT trial had a more robust protocol and inclusion criteria, making its findings more reliable.
The REBOOT trial challenges over 40 years of standard clinical practice, which has recommended initiating beta blockers for patients admitted to the hospital for a heart attack. Experts assert that the treatment landscape has evolved significantly over the past 10-20 years with advancements in cardiology techniques and medication effectiveness. Dr. Fonarow remarked that beta blockers were developed before the adoption of routine reperfusion therapy for acute heart attacks, and current practices may necessitate a reevaluation of beta blocker protocols.
Dr. Pfau concluded that neither study convincingly supports the use of beta blockers in this select patient group. "If beta blockers have an effect, it is likely minimal given the other available therapies," he explained. For now, patients who can safely take beta blockers should continue their use, according to Dr. Fonarow, who also called for further research to identify which patients may benefit most from beta blocker therapy.
As the field of cardiology continues to evolve, these studies highlight the importance of ongoing research into the best treatment options for patients recovering from heart attacks.
