New research unveiled at the European Society of Cardiology (ESC) Congress 2025 is shaking up the understanding of how women fare following a heart attack. The findings emphasize concerning disparities in health outcomes between genders, particularly regarding the use of beta-blockers.

The study, derived from an analysis of the REBOOT clinical trial, reveals a troubling truth: women suffering a myocardial infarction (MI) experience worse health outcomes post-event than men. Alarmingly, those who were treated with beta-blockers faced an increased risk of mortality, reinfarction, and hospitalization for heart failure compared to their female counterparts not on this medication.

Dr. Valentín Fuster, a leading investigator and president of the Mount Sinai Foster Heart Hospital, emphasized the significance of these findings. He stated, "We've been exploring sex differences in cardiovascular disease for years. This study clearly shows that medication responses differ fundamentally between women and men, signaling the urgent need for sex-specific strategies in treating cardiovascular conditions."

Launched in 2018, the REBOOT trial aimed to investigate the effects of beta-blockers in heart failure patients with reduced ejection fraction. Presented at the ESC Congress and concurrently published in the New England Journal of Medicine, the full results indicated no significant difference in overall mortality or heart failure admissions between those on beta-blockers versus those without them.

However, when delving deeper into the data with a post hoc analysis, shocking revelations about gender disparities emerged. Out of 8,438 patients in the trial, 1,627 were women who, on average, were older and had more comorbidities, receiving fewer guideline-recommended therapies compared to men.

The data also illustrated concerning rates of adverse outcomes. Women in the beta-blocker group experienced a striking incidence rate of 30.4 per 1,000 patient-years, significantly higher than the 21.0 per 1,000 patient-years seen in women not on beta-blockers.

The excess risks for women were largely driven by increased mortality rates, particularly among those with preserved left ventricular ejection fraction and those on higher doses of beta-blockers. Dr. Xavier Rosselló, also involved in the study, echoed the pressing need for a tailored approach, stating, "A one-size-fits-all strategy is ineffective; we must consider sex-specific factors in prescribing cardiovascular interventions."

As the medical community grapples with these groundbreaking findings, the future of cardiovascular treatment may need a radical shift to ensure the health and well-being of women post-heart attack.