This news might break your heart — literally.
A shocking new study found that the go-to treatment doctors have been using to manage heart attacks for the last 40 years may offer no real benefit for many patients.
Even more alarming, the research suggests that women who receive the drug may face a higher risk of complications, including death.
In the US, someone suffers a heart attack — known medically as a myocardial infarction — every 40 seconds. That adds up to a staggering 805,000 Americans each year, according to the CDC.
“Currently, more than 80% of patients with uncomplicated myocardial infarction are discharged on beta blockers,” Dr. Borja Ibáñez, principal investigator of the “REBOOT” trial, said in a statement.
These medications, which work by slowing the heart rate and lowering blood pressure, are often prescribed for at least a year — and in many cases, for life — based on older studies that suggested they could curb the risk of a second heart attack or death.
“Their benefits were linked to reduced cardiac oxygen demand and arrhythmia prevention,” Ibáñez explained, “but therapies have evolved.”
Today, he noted, clogged arteries — the leading cause of heart attacks — can often be quickly reopened thanks to advanced procedures, cutting the risk of serious complications like arrhythmias, or irregular heartbeats.
“In this new context — where the extent of heart damage is smaller — the need for beta blockers is unclear,” he said.
But now, thanks to the REBOOT trial, scientists may finally be getting a better idea.
In the study, Ibáñez and his team enrolled 8,505 heart attack patients from 109 hospitals in Spain and Italy. All of them had suffered a heart attack but retained normal cardiac function afterward.
Half were randomly assigned to take beta blockers after hospital discharge, while the other half were not. Otherwise, every patient received the current standard of care and was followed for nearly four years.
By the end of the study, researchers found no major differences in the rate of death, repeat heart attacks or hospitalizations for heart failure between the two groups.
That’s a major blow to a treatment long considered routine, raising serious doubts about whether the drug actually benefits patients with normal heart function — who make up about 80% of survivors after a first heart attack.
Although generally considered safe, beta blockers can cause side effects like fatigue, a low heart rate, and sexual dysfunction.
“While we often test new drugs, it’s much less common to rigorously question the continued need for older treatments,” Ibáñez said.
“The trial was designed to optimize heart attack care based on solid scientific evidence and without commercial interests,” he added, noting it was conducted with no funding from the pharmaceutical industry.
Digging deeper into the data, researchers uncovered a shocking twist: women with minimal cardiovascular damage after their heart attacks who took beta blockers actually fared worse.
These women faced a higher risk of suffering another heart attack — which is far more dangerous than the first — or being hospitalized for heart failure compared to those who skipped the drug.
In fact, their chances of dying were 2.7% higher during the follow-up period.
Notably, however, this increased risk didn’t appear in women who suffered mild heart damage after a heart attack.
Men also showed no signs of this heightened danger after taking beta blockers.
“That’s actually not surprising,” Dr. Andrew Freeman, director of cardiovascular prevention and wellness at National Jewish Health, told CNN Health.
“Gender has a lot to do with how people respond to medication. In many cases, women have smaller hearts. They’re more sensitive to blood pressure medications. Some of that may have to do with size, and some may have to do with other factors we have yet to fully understand,” he explained.
The researchers also pointed out that women in the REBOOT trial were generally older, sicker and got less aggressive treatment for heart attacks than men. All of these factors, they said, could help explain their higher risk.
Still, Ibáñez said the study will “change clinical practice worldwide,” calling the findings “one of the most significant advances in heart attack treatment in decades.”
“These results will help streamline treatment, reduce side effects, and improve quality of life for thousands of patients every year,” he added.
