A groundbreaking analysis from the REBOOT clinical trial, coordinated by the Centro Nacional de Investigaciones Cardiovasculares (CNIC), has revealed significant sex-specific differences in the effects of beta-blockers following heart attacks. Published in the European Heart Journal, the study raises critical questions about established treatment practices for women. The findings were presented at the European Society of Cardiology (ESC) congress in Madrid.
The REBOOT trial, the largest of its kind, involved 8,505 patients across 109 hospitals in Spain and Italy. It focused on patients who survived myocardial infarction without moderate or severe cardiac function deterioration. While the trial included a smaller proportion of women, it remains the largest study to date testing beta-blockers in female patients post-infarction. Participants were randomly assigned to receive either beta-blockers or no beta-blockers, alongside standard post-heart attack care, and were followed for a median of nearly four years.
Key Findings and Implications
The analysis uncovered that while men experienced no significant benefit or risk from beta-blocker treatment, women faced a markedly increased risk of adverse outcomes. Specifically, women treated with beta-blockers had a 2.7% higher absolute risk of mortality compared to those not receiving the drug over the study’s 3.7-year follow-up period. The increased risk was particularly pronounced in women with completely normal cardiac function post-infarction.
“These findings confirm previous observational data but in a rigorous prospective trial: women presenting with infarction have worse cardiovascular profiles and, more importantly, have worse prognosis than men,” said Dr. Borja Ibáñez, CNIC Scientific Director and Principal Investigator of the REBOOT trial.
Dr. Ibáñez emphasized the need for clinicians to carefully consider the risks and benefits of prescribing beta-blockers to female patients, suggesting that alternative therapies or dose adjustments might be necessary.
Sex-Specific Differences in Cardiovascular Health
The trial also highlighted broader sex-specific differences in cardiovascular health. Women in the study were generally older, had more comorbidities, and were more likely to experience heart attacks without obstructive coronary arteries compared to men. Despite high overall prescription rates of secondary prevention interventions, women were less frequently prescribed certain guideline-recommended therapies, such as antiplatelets and statins.
“Our findings suggest that a one-size-fits-all approach may not be appropriate and that sex-specific considerations are crucial for cardiovascular interventions prescriptions,” stated Xavier Rosselló, a scientist at CNIC and co-leader of the REBOOT trial.
Dr. Valentín Fuster, CNIC General Director and another investigator of the trial, noted the importance of these findings in advancing a sex-specific approach to cardiovascular disease treatment. “This study should spark the much-needed sex-specific approach for cardiovascular disease,” he remarked.
Broader Impact on Treatment Guidelines
The REBOOT trial’s results underscore the importance of personalizing post-heart attack therapy. By revealing how sex-specific factors influence the safety and effectiveness of commonly used drugs, the study could reshape treatment guidelines and improve outcomes for women worldwide. The trial was funded by the CNIC, affiliated with the Carlos III Health Institute, and conducted in collaboration with the Spanish Society of Cardiology and CIBERCV.
The CNIC, recognized as a Severo Ochoa center of excellence, continues to lead in cardiovascular research, translating findings into real-world benefits for patients. This study represents a significant step in understanding and addressing the unique cardiovascular needs of women, potentially leading to more effective and safer treatment protocols.
