REDUCE-AMI: No Benefit to Beta Blockers Post-Myocardial Infarction If LVEF is Normal

Troels Yndigegn, MD
Credit: American College of Cardiology

Use of beta-blockers following myocardial infarction does not provide significant benefit for patients with a normal left ventricular ejection fraction (LVEF), according to results of the REDUCE-AMI trial.

A parallel-group, open-label trial assessing the effect of long-term beta-blocker use, results of the trial, which were presented at the American College of Cardiology 2024 (ACC.24) Annual Scientific Sessions, suggest long-term beta-blocker use was not associated with a significant reduction in risk of all-cause mortality or new myocardial infarction among patients with an LVEF of 50% or greater.

“I think that, following this study, many doctors will not find an indication to routinely treat all their patients with beta blockers following a heart attack,” said lead investigator Troels Yndigegn, MD, interventional cardiologist at Lund University in Sweden.²

For decades, the cardiology community has held true to the findings of landmark trials from the 1980s, purporting a benefit of long-term beta blocker use in patients with myocardial infarctions. As cited within the investigators’ manuscript, advances in management of post-myocardial infarction patient populations, including PCIs, hsCTN, RAAS blockade, high-intensity statins, and more, many within the field have questioned the benefit of beta-blocker use. Of note, investigators cite a meta-analysis suggesting long-term beta-blocker use failed to provide benefit in the era of modern reperfusion strategies.¹

With this in mind, the investigators launched the Randomized Evaluation of Decreased Usage of Beta-Blockers after Acute Myocardial Infarction (REDUCE-AMI) study. A registry-based, prospective, open-label, parallel-group, randomized clinical trial, REDUCE-AMI was conducted across 45 centers in 3 countries. The trial included adult patients from the SWEDEHEART registry who provided written informed consent 1 to 7 days after myocardial infarction and who had undergone coronary angiography and echocardiography with a preserved LVEF.¹

Patients included in the trial were randomized in a 1:1 ratio to long-term beta-blocker or no beta-blocker. The primary outcome of interest for the trial was a composite of all-cause mortality or new myocardial infarction. The trial also included multiple secondary outcomes of interest, such as all-cause mortality, cardiovascular mortality, myocardial infarction, hospitalization for atrial fibrillation, and hospitalization for heart failure.¹

From September 2017 through May 2023, investigators enrolled a total of 5020 patients. Of note the majority of these patients (95.4%) were from Sweden. This cohort had a median age of 65 years, 22.5% were women, 35.2% had an ST-segment elevation myocardial infarction, and the median follow-up was 3.5 (Interquartile Range, 2.2 to 4.7) years. Investigators pointed out 2508 patients were randomized to beta-blockers and 2512 were randomized to no beta-blockers.¹

Results of the study suggested a primary outcome event occurred among 7.9% of the beta-blocker group and among 8.3% of the no–beta-blocker group (hazard ratio [HR], 0.96; 95% confidence interval [CI], 0.79 to 1.16; P = .64). Further analysis suggested the long-term beta-blocker strategy did not contribute to a reduced incidence of all-cause mortality (3.9% in the beta-blocker group and 4.1% in the no– beta-blocker group), cardiovascular mortality (1.5% and 1.3%, respectively), myocardial infarction (4.5% and 4.7%, respectively) hospitalization for atrial fibrillation (1.1% and 1.4%, respectively) and hospitalization for heart failure (0.8% and 0.9%, respectively).¹

Safety analyses of the trial suggested hospitalization for bradycardia, second- or third-degree atrioventricular block, hypotension, syncope, or implantation of a pacemaker occurred among 3.4% of the beta-blocker group and 3.2% of the no–beta-blocker group. Additionally, investigators noted asthma or chronic obstructive pulmonary disease occurred among 0.6% in both groups while hospitalization for stroke occurred among 1.4% and 1.8% of the beta-blocker and no-beta-blocker groups, respectively.¹

“We believe that the evidence still supports beta blockers for patients with a large myocardial infarction that experience heart failure, but for patients with no signs of heart failure and a normal ejection fraction, this trial establishes that there’s no indication that routine use of beta blockers is beneficial," Yndigegn added.²

References:

1. Yndigegn T, Lindahl B, Mars K, et al. Long-term Beta-blocker Treatment After Acute Myocardial Infarction And Preserved Left Ventricular Ejection Fraction - The REDUCE-AMI Trial. . Presented at: American College of Cardiology (ACC.24) Annual Scientific Session. April 6 – 8, 2024. Atlanta, GA.
2. American College of Cardiology. Beta blockers may not benefit many heart attack survivors. American College of Cardiology. April 7, 2024. Accessed April 7, 2024. https://www.acc.org/About-ACC/Press-Releases/2024/04/07/14/12/beta-blockers-may-not-benefit-many-heart-attack-survivors.