April 8, 2024 – Taking beta-blockers after a heart attack does not prevent death or a second heart attack in people with normal heart pumping function, as evidenced by an ejection fraction greater than 50% The published study found that the risk of In Annual Scientific Sessions of the American College of Cardiology.

The findings call into question the routine use of beta-blockers for all patients after a heart attack, which have been the mainstay of treatment for decades. Approximately 50% of heart attack survivors do not experience heart failure. In these patients, no difference was found in the composite primary endpoint of death from any cause or new nonfatal heart attack between those who were prescribed beta-blockers and those who were not.

Troell’s Indigen, Maryland

“After this study, I don’t think many doctors will find an indication to routinely treat all patients with beta-blockers after a heart attack,” said Dr. said Troels Indigen, MD, lead author of the study. “While we believe there is still evidence to support the efficacy of beta-blockers in patients with massive myocardial infarction who develop heart failure, this Trials have shown that there is no indication that routine use of beta-blockers is “beneficial”. ”

Heart failure occurs when the heart muscle becomes too weak or stiff to pump blood effectively. This is primarily evaluated in terms of left ventricular ejection fraction, which is the percentage of blood that is forced out of the heart’s left ventricle with each heartbeat. An ejection fraction greater than 40% to 50% is considered normal.

Beta-blockers lower blood pressure by inhibiting certain hormones, such as adrenaline, which increase the speed of the heart. Based on evidence that beta-blockers help prevent secondary heart attacks, many clinicians recommend that all patients receive beta-blockers after a heart attack, usually for at least 1 year and often for the rest of the patient’s life. Prescribe a blocker. However, researchers said the clinical trials that led to the routine use of beta-blockers were conducted before the advent of many new procedures now widely used to open blocked arteries.

“At that time, the damage to the heart muscle was greater than it is today, and there was no possibility of revascularizing patients with percutaneous coronary interventions or stents as we do today,” Indigen said. “What we’re seeing today is more myocardial infarctions that are smaller and don’t do the same amount of damage to the heart muscle.”

To elucidate the potential benefits of beta-blockers in light of this changing landscape, the REDUCEAMI study will focus on 45 centers in Sweden, Estonia and New Zealand treating acute heart attacks participating in the SWEDEHEART registry. We enrolled 5,020 patients. All patients had an ejection fraction of 50% or higher, as assessed by echocardiogram performed within 1 week after the heart attack. Half were randomly assigned to receive long-term beta-blockers, and the remainder received no beta-blockers.

Over a median follow-up of 3.5 years, there were no significant differences between the groups in rates of the composite primary endpoint or secondary clinical endpoints, including heart failure, atrial fibrillation, and symptoms such as chest pain and shortness of breath. There were also no differences in safety endpoints such as stroke, abnormally low blood pressure, and syncope.

The researchers believe that the lack of benefits associated with beta-blockers observed in this patient group frees many patients from the burden of taking these drugs and avoids side effects such as mood disorders, fatigue, and sexual dysfunction. He said it could be avoided.

“We believe this discovery will impact thousands of patients, as many patients are reporting side effects or suspected side effects from these drugs,” Indigen said.

The study did not include a placebo control, and participants knew which group they were assigned to. Although this open-label approach could potentially introduce bias, the researchers said this was unlikely to affect outcomes such as death or heart attacks. Professor Indigen said the results should be generalizable beyond the population in which the study was conducted, and other observational studies are underway to help clarify the routine use of beta-blockers in diverse populations. He added that it was inside.

The researchers plan to analyze outcomes for quality of life and sexual health separately. This study was funded by the Swedish Research Council, the Swedish Heart and Lung Foundation, and the Stockholm County Council. The study was published online in the New England Journal of Medicine upon publication.

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