The REBOOT trial concludes, published in “The New England Journal of Medicine”, with the participation of Dr. José María de la Torre Hernández, Head of Cardiology at Valdecilla Hospital
One of the most widespread practices in modern cardiology—the routine use of beta-blockers after a myocardial infarction—has been called into question thanks to the results of the REBOOT clinical trial. The study involved Dr. José María de la Torre, Head of the Cardiology Department at Marqués de Valdecilla University Hospital, who served as a member of the study’s steering committee, alongside a team of cardiologists from the hospital who carried out the trial, placing it among the ten centers with the highest number of enrolled patients.
The results, published in “The New England Journal of Medicine”, show that these drugs provide no clinical benefit when the ejection fraction—the heart’s pumping ability—is above 50%, meaning that cardiac function remains preserved after a heart attack.
However, the researchers emphasize that beta-blockers remain indicated when the ejection fraction is lower or in cases of heart failure, since in these situations they do improve survival and reduce complications.
“The message should be clear: beta-blockers offer no benefit after a heart attack if the residual ejection fraction is greater than 50%, but they are highly recommended when the heart is damaged and the ejection fraction is reduced,” summarizes Dr. De la Torre. “That distinction is essential to avoid alarm and misinterpretation.”
It is important to note, however, that some patients with a heart attack and an ejection fraction above 50% may still have other indications for these drugs, such as hypertension or certain types of arrhythmias.
Any patient currently taking these medications and who has doubts about their treatment should consult their physician.
A study of international significance
The REBOOT trial, coordinated by the National Center for Cardiovascular Research (CNIC) under the direction of Dr. Borja Ibáñez, included 8,505 patients from 109 hospitals in Spain and Italy, with an average follow-up of 3.7 years. It is one of the largest cardiovascular studies conducted in recent decades.
Until now, international clinical guidelines recommended the routine prescription of beta-blockers after a heart attack—a practice based on studies conducted more than 40 years ago, before the era of immediate reperfusion, statins, and dual antiplatelet therapy. Today, more than 80% of patients receive these drugs at discharge, even though they can cause adverse effects such as fatigue, bradycardia, or sexual dysfunction.
The findings of REBOOT challenge this long-standing dogma and open the door to more personalized medicine, tailored to each patient’s clinical profile.
Main results
The study found no significant differences between patients treated with beta-blockers and those who did not receive them in terms of:
• Overall mortality.
• Risk of reinfarction.
• Hospitalization for heart failure.
In patients with preserved ejection fraction, beta-blockers did not reduce any of these events, making these results a paradigm shift in cardiology.
Sub-analyses and future research directions
The trial included sub-analyses suggesting possible gender differences in treatment response. According to Dr. De la Torre, “women with preserved ejection fraction appeared to experience more adverse effects from beta-blockers, especially at high doses.” Although these findings must be confirmed in dedicated studies, they pave the way for future research focused on the impact of gender on cardiovascular therapy.
Other ongoing sub-studies will analyze how these drugs perform according to the type of heart attack, leveraging the scope and richness of data generated by such a large cohort.
Spain at the forefront of global research
The publication of REBOOT in the world’s most prestigious medical journal and its presentation at the European Society of Cardiology Congress—the largest in the world, with over 34,000 attendees—highlight Spain’s leading role in cardiovascular research.
“The impact of this work is enormous, both in clinical practice and in the international visibility of Spanish science,” says Dr. De la Torre. “It is a source of pride that a study changing the way we treat patients has been led from our country.”
