Women with heart issues on beta blockers face higher risk of death, study finds

Women treated with beta blockers had a higher risk of death, heart attack or hospitalisation for heart failure compared to women not receiving the drug, a recent study found.

Men, meanwhile, did not face this increased risk, the study showed.

The research also showed that beta blockers provide no clinical benefit for patients who have had an uncomplicated myocardial infarction with preserved heart function.

Beta blockers have been the standard treatment for these patients for 40 years.

The study results, which could overturn a standard treatment paradigm, were presented on Saturday, August 30, during a “Hot Line” session at the European Society of Cardiology Congress in Madrid.

Principal Investigator Borja Ibáñez, MD, CNIC’s Scientific Director, who presented the results, said: “Currently, more than 80 percent of patients with uncomplicated myocardial infarction are discharged on beta blockers.

“The REBOOT findings represent one of the most significant advances in heart attack treatment in decades.”

Although generally considered safe, beta blockers can cause side effects such as fatigue, bradycardia (low heart rate), and sexual dysfunction.

For more than 40 years, beta blockers have been prescribed as a standard treatment after a heart attack, but their benefit in the context of modern treatments was unproven.

The REBOOT trial, is the largest clinical trial on this subject.

The international study was coordinated by CNIC in collaboration with the Mario Negri Institute for Pharmacological Research in Milan.

Researchers enrolled 8,505 patients across 109 hospitals in Spain and Italy.

Participants were randomly assigned to receive or not receive beta blockers after hospital discharge.

All patients otherwise received the current standard of care and were followed for a median of nearly four years.

The results showed no significant differences between the two groups in rates of death, recurrent heart attack, or hospitalisation for heart failure.

A REBOOT subgroup analysis found that women treated with beta blockers experienced more adverse events.

Results show women treated with beta-blockers had a 2.7 percent higher absolute risk of mortality compared to those not treated with beta-blockers during the 3.7 years of follow-up of the study.

The elevated risk when treated with beta-blockers was restricted to women with a complete normal cardiac function after a heart attack (left ventricular ejection fraction of 50 percent or higher).

Those with a mild deterioration in cardiac function did not have an excess risk of adverse outcomes when treated with beta-blockers.