Long-term use of beta-blockers in patients with acute myocardial infarction (MI) with a preserved left ventricular ejection fraction (LVEF) of 50% or more did not reduce the risk of death or second heart attack, a study found. It was suggested.

This prospective, randomized, open-label, parallel-group study New England Medical Journal The April 7, 2024 study included 5,020 participants with coronary angiography-confirmed acute MI from September 2019 to May 2023 at 45 sites in Sweden, Estonia, and New Zealand. Ta.

Participants were randomly assigned to receive long-term treatment with a beta-blocker (metoprolol or bisoprolol) or no treatment with a beta-blocker over a median period of 3.5 years (range 2.2-4.7 years). Followed up.

The study’s primary endpoint was a combination of death from any cause or new myocardial infarction. Secondary endpoints included death from any cause, death from cardiovascular disease, new myocardial infarction, and hospitalization for atrial fibrillation or heart failure.

In this study, researchers found that death or another MI occurred in 199 people (7.9%) in the beta-blocker group and 208 (8.3%) in the non-beta-blocker group (hazard ratio ) [HR]: 0.96 (95% confidence interval [CI]); P=0.64).

The researchers also reported that beta-blockers did not appear to reduce the cumulative incidence of secondary endpoints with similar safety endpoints between the two groups (3.4% in the beta-blocker group; (3.2% in the group without beta-blockers).

Commenting on the study, Paul Wright, Chief Cardiac Pharmacist at Barts Health NHS Trust, said: “This is an interesting study that addresses the long-term question of the benefit of beta-blockers for all patients after acute myocardial infarction.

“It should be noted that the original beta-blocker data date from the pre-primary percutaneous coronary intervention (PPCI) era, when many patients received medical or fibrinolytic therapy; “Many have left ventricular dysfunction and therefore support the use of beta-blockers,” he added.

“The lack of heart failure after acute MI and PPCI indicates loss of efficacy of established gold standard treatments.

“Perhaps guidelines need to reflect a more patient-tailored approach and recommend treatments for comorbidities, not just events that are indicative of AMI. You will need to make adjustments.”

Current guidance on acute coronary syndromes from the National Institute for Health and Care Excellence states that beta-blockers should be given for at least 12 months after MI for people whose LVEF has not decreased.

However, due to the lack of direct evidence regarding the optimal duration of beta-blocker administration, we do not recommend a definite time to discontinue treatment.

Commenting on the study findings, Anna Mann, Lead Pharmacist for Clinical and Cardiothoracic Services at Mid and South Essex NHS Foundation Trust, said: “This study shows that patients with preserved EF may not need beta-blockers, as well as those at high risk or with impaired EF.

“This means lower drug costs and eases the drug burden for patients who are already taking other secondary prevention drugs,” she added.

“However, it is noteworthy that the authors state that the doses used in this study were “lower than in previous trials,” and that they aim for at least 100 mg of metoprolol and 5 mg of bisoprolol.

“This suggests that the maximum dose was not being used. Although this study did not show a significant mortality benefit with beta-blockers, this automatically rules them out.” “You shouldn’t,” Mann advised.