THURSDAY, May 4, 2023 (HealthDay News) -- It's standard for heart attack survivors to take beta blocker medications for years afterward, but a new study suggests that may be unnecessary for people who've had a milder heart attack.
Researchers found that among heart attack survivors whose hearts still had normal pumping ability, there was no added benefit from using beta blockers for more than one year. They were no less likely to die or suffer a repeat heart attack than patients who were not on beta blockers long term.
Experts said the findings, published May 2 in the medical journal Heart, are not enough to change treatment guidelines.
But it's also "reasonable" for patients on beta blockers to ask their doctor why they're using the medication, and whether continuing is necessary, said Dr. Ajay Kirtane.
Kirtane, who was not involved in the study, is a member of the American College of Cardiology's Interventional Council and a professor at Columbia University Irving Medical Center, in New York City.
"It's difficult for patients to be on a lot of medications," Kirtane said. So if there's a way to "streamline" a post-heart-attack drug regimen, he added, that's important.
Beta blockers are among the most widely prescribed medications, and include drugs like atenolol, carvedilol and metoprolol. They help protect the heart by blocking the effects of "stress" hormones, slowing down heart rate and making it easier for the heart muscle to contract.
Studies have shown that beta blockers improve the outlook for heart attack survivors who have heart failure — a progressive weakening in the heart's pumping ability.
But it hasn't been clear whether long-term use helps people who've had a milder heart attack that left the heart muscle's pumping capacity intact.
The practice of keeping those patients on beta blockers is based on older trials — predating some of the other treatments available now, explained study author Dr. Gorav Batra, a cardiologist at Uppsala University, in Sweden.
Those treatments include procedures to clear clogged heart arteries and medications to help prevent future blood clots.
So, Batra and his colleagues studied the question by looking at data from a Swedish national registry of heart attack patients. It included over 43,000 people who'd suffered a heart attack but had a normal "ejection fraction" — an indicator of how well the heart is pumping.
Most of the patients — over 78% — were on beta blockers for over a year, while the rest were not on the medications long-term.
On average, the study found, both groups of patients fared similarly over 4.5 years. People not on long-term beta blockers actually had a lower rate of death, repeat heart attack, heart failure or emergency heart procedure: They suffered those problems at a rate of just under 4% per year, versus just under 5% per year among people on long-term beta blockers.
Batra cautioned that the study was not a clinical trial. That is, it didn't randomly assign some patients to stay on beta-blockers, and others to stop — so it cannot prove that long-term use has no benefits for people with milder heart attacks.
"As it is not a trial, this study should not change practice," Batra said.
But, he added, it does raise an "important question" that should be tested in future trials.
Kirtane agreed. He also said that people with milder heart attacks may still benefit from beta blockers in the short term: They may, in fact, have some reduction in the heart's pumping ability right after the heart attack.
"It would be a bridge too far to say that we shouldn't prescribe these drugs at all," Kirtane said.
But, he added, patients who have been on a beta blocker for a year or more could ask their doctor whether it's still necessary.
Beta blockers can have side effects like fatigue and dizziness, Kirtane noted, so if the medications are not needed, people can avoid those problems.
The American Heart Association has more on heart attack recovery.
SOURCES: Gorav Batra, MD, PhD, consultant cardiologist, postdoctoral researcher, Uppsala University, Uppsala, Sweden; Ajay Kirtane, MD, professor, medicine, Columbia University Irving Medical Center, New York City, member, Interventional Council, American College of Cardiology, Washington, D.C.; Heart, May 2, 2023, online