No effect of beta-blockers after myocardial infarction with preserved cardiac function

Troels Yndigegn.

Long-term treatment with beta-blockers for patients who have had an acute myocardial infarction but afterwards have preserved heart function does not affect the risk of them suffering a new heart attack or dying. This is shown in a new study published in the New England Journal of Medicine, with Troels Yndigegn, doctor at Skåne University Hospital and researcher at Lund University, as the first author.

Beta-Blockers after Myocardial Infarction and Preserved Ejection Fraction (www.nejm.org)

The REDUCE study, conducted by researchers at several hospitals and universities in Sweden, Estonia, and New Zealand, examined the effects of long-term treatment with beta-blockers in patients who have had an acute myocardial infarction but afterwards have preserved heart function.

Over 5,000 patients, of which about 500 were from hospitals in the Skåne Region, participated in the study and were randomly assigned to either receive standard treatment with beta-blockers or not. The researchers then followed the patients for up to five years, looking at mortality, new heart attacks, heart failure, and atrial fibrillation among other things.

"The results show that long-term treatment with beta-blockers does not reduce the risk of death or new heart attacks in the participants. Although beta-blockers have traditionally been used as standard treatment after a heart attack, the study shows that there is no clear benefit for this specific patient group," says Troels Yndigegn, who was the responsible investigator and coordinator of the study.

Can avoid unnecessary treatment

Nearly 20,000 patients suffer a heart attack annually in Sweden, and up to half of these have preserved heart function afterward. Beta-blockers have historically been part of the treatment for all patients after a heart attack. The drugs block receptors in blood vessels and the heart, thereby limiting the effect of various stress hormones. This allows the heart to work more efficiently, and blood pressure and pulse to decrease.

The routine treatment with beta-blockers is based on older studies that showed the treatment was beneficial, primarily for patients with damage to the heart muscle.

"Now that the study has shown that those with preserved heart function do not benefit from beta-blockers, patients can avoid unnecessary treatment, a treatment that often entails the risk of side effects," says Troels Yndigegn.

Examples of side effects include slow heart rhythm, fatigue, headache, dizziness, nausea, vomiting, diarrhea, cold hands and feet, sleep problems, and nightmares.

Affects future treatment guidelines

The results of the study, which were presented at the American College of Cardiology Conference on April 7, will influence the treatment of patients with myocardial infarction in the future.

"The results will contribute to guiding future treatment guidelines for myocardial infarction patients with preserved heart function," says Troels Yndigegn.

Facts about REDUCE

The study began at the end of 2017 and continued until the beginning of 2023. In Sweden, patients from 38 hospitals participated. Study data comes from the Swedeheart healthcare quality register.
Tomas Jernberg, a professor at the Karolinska Institute, was responsible for the study, with Troels Yndigegn and David Erlinge, a senior physician at Skåne University Hospital and professor at Lund University, leading the work. The study was funded by the Swedish Research Council and the Heart-Lung Foundation.