BACKGROUND: Most trials that have shown a benefit of beta-blocker treatment after myocardial infarction included patients with large myocardial infarctions and were conducted in an era before modern biomarker-based diagnosis of myocardial infarction and treatment with percutaneous coronary intervention, antithrombotic agents, high-intensity statins, and renin-angiotensin-aldosterone system antagonists.
METHODS: In a parallel-group, open-label trial performed at 45 centers in Sweden, Estonia, and New Zealand, we randomly assigned patients with an acute myocardial infarction who had undergone coronary angiography and had a left ventricular ejection fraction of at least 50% to receive either long-term treatment with a beta-blocker (metoprolol or bisoprolol) or no beta-blocker treatment. The primary end point was a composite of death from any cause or new myocardial infarction.
RESULTS: From September 2017 through May 2023, a total of 5020 patients were enrolled (95.4% of whom were from Sweden). The median follow-up was 3.5 years (interquartile range, 2.2 to 4.7). A primary end-point event occurred in 199 of 2508 patients (7.9%) in the beta-blocker group and in 208 of 2512 patients (8.3%) in the no-beta-blocker group (hazard ratio, 0.96; 95% confidence interval, 0.79 to 1.16; P = 0.64). Beta-blocker treatment did not appear to lead to a lower cumulative incidence of the secondary end points (death from any cause, 3.9% in the beta-blocker group and 4.1% in the no-beta-blocker group; death from cardiovascular causes, 1.5% and 1.3%, respectively; myocardial infarction, 4.5% and 4.7%; hospitalization for atrial fibrillation, 1.1% and 1.4%; and hospitalization for heart failure, 0.8% and 0.9%). With regard to safety end points, hospitalization for bradycardia, second- or third-degree atrioventricular block, hypotension, syncope, or implantation of a pacemaker occurred in 3.4% of the patients in the beta-blocker group and in 3.2% of those in the no-beta-blocker group; hospitalization for asthma or chronic obstructive pulmonary disease in 0.6% and 0.6%, respectively; and hospitalization for stroke in 1.4% and 1.8%.
CONCLUSIONS: Among patients with acute myocardial infarction who underwent early coronary angiography and had a preserved left ventricular ejection fraction (=50%), long-term beta-blocker treatment did not lead to a lower risk of the composite primary end point of death from any cause or new myocardial infarction than no beta-blocker use. (Funded by the Swedish Research Council and others; REDUCE-AMI ClinicalTrials.gov number, NCT03278509.).
| Discipline Area | Score |
|---|---|
| Internal Medicine |  |
| Cardiology |  |
It's not a surprise that beta-blockers are not helpful.
This is a useful trial that may change management priorities.
This is a very important contribution because it goes against conventional teaching about using beta blockade. This well conducted study upends an important cornerstone of medical treatment after cardiac events. The fact that beta blockade did not change or improve cardiovascular outcomes needs to be widely propagated. This may also go against guidelines about goal-directed therapy.
An important reminder that 'strong evidence' can be ephemeral as knowledge and medical practice advances.
Conventional wisdom and recommendations have always said that beta-blockade would be beneficial in people who have ischemic heart disease; however, beta-blockers are generally not 1st or 2nd line in hypertension. This was a well designed and very large study that showed that patients receiving beta-blockade who had normal ejection fraction and interventions for their coronary disease did not benefit from being placed on a beta-blocker. This is very important to my hospitalist colleagues who manage patients with acute coronary disease as well as those with side effects from beta-blockers since these do not appear to be necessary to prevent events, confirming the results from the SWEDEHEART study.
This trial should be treated as hypothesis-generating; it's certainly not definitive evidence. This trial was open-label and under-powered for detecting a difference. Also, there was a fair amount of cross-over, that would skew toward finding no difference between the groups. In terms of applicability, keep in mind that a Scandanavian trial group may not reflect your patient population.