Groundbreaking Research Reveals Beta-Blockers May Increase Risk of Hospitalization and Death for Women After Heart Attacks

Groundbreaking research has revealed that beta-blockers, a widely used treatment for heart attack patients, may not benefit the majority of individuals and could potentially increase hospitalization and mortality risks in certain female patients, while having no such effect on men.

The study’s senior author, Dr. Valentin Fuster, President of Mount Sinai Fuster Heart Hospital in New York City and Director General of the National Center for Cardiovascular Investigation in Madrid, stated, “These findings will significantly influence international clinical guidelines regarding beta-blocker use in both men and women, and could stimulate a long-overdue, sex-specific approach to cardiovascular disease treatment.”

In the European Heart Journal and slated for presentation at the European Society of Cardiology Congress in Madrid this weekend, the research indicates that female heart attack survivors with little damage who were administered beta-blockers had significantly higher rates of recurrent heart attacks, hospitalization for heart failure, and a nearly threefold increased risk of death compared to those not receiving the drug.

Dr. Borja Ibáñez, the study’s lead author and Scientific Director for Madrid’s National Center for Cardiovascular Investigation, explained, “This was particularly true for women receiving high doses of beta-blockers.”

The study’s findings only applied to female patients with a left ventricular ejection fraction above 50%, indicating normal heart function. Ejection fraction measures the heart’s ability to pump oxygenated blood efficiently throughout the body. However, for those with a score below 40% after a heart attack, beta-blockers remain the standard of care due to their effectiveness in managing potentially triggering heart arrhythmias.

Dr. Andrew Freeman, Director of Cardiovascular Prevention and Wellness at National Jewish Health in Denver, noted potential side effects associated with the drug: “Beta-blockers can lead to low blood pressure, low heart rate, erectile dysfunction, fatigue, and mood swings. Whenever we use these drugs, we must always weigh risk against benefit.”

The increased susceptibility of women to harm from beta-blockers compared to men may be due to gender differences in medication response. Dr. Freeman explained, “Women tend to be more sensitive to blood pressure medications because they often have smaller hearts and other as-yet-unexplored factors.”

Historically, early heart research primarily focused on males, leading to years of delay before the medical community recognized that heart disease manifests differently in women. Men typically exhibit plaque buildup in major arteries and traditional heart attack symptoms such as chest pain. In contrast, women are more likely to have plaque in smaller blood vessels and may experience atypical symptoms like back pain, indigestion, or shortness of breath.

The study’s analysis on women was part of a larger clinical trial called REBOOT — Treatment with Beta-Blockers after Myocardial Infarction without Reduced Ejection Fraction — which followed 8,505 male and female heart attack patients treated at 109 hospitals in Spain and Italy for nearly four years.

The study’s results were also published in The New England Journal of Medicine and presented at the European Society of Cardiology Congress. None of the trial participants had a left ventricular ejection fraction below 40%, suggesting potential heart failure.

“We found no benefit in using beta-blockers for men or women with preserved heart function after heart attack, despite this treatment being the standard for nearly four decades,” said Fuster, former editor-in-chief of the Journal of the American College of Cardiology and past president of the American Heart Association and the World Health Federation.

This lack of benefit is likely due to advancements in medication treatments such as immediate stent and blood thinner usage upon hospital arrival. Most heart attack survivors today have left ventricular ejection fractions above 50%. However, approximately 80% of patients in the US, Europe, and Asia are still treated with beta-blockers based on current medical guidelines.

“While we routinely test new drugs, it’s less common to critically evaluate the continued need for older treatments,” Ibáñez said.