Effectiveness of Beta Blockers in Preventing Cardiovascular Problems in Patients with a History of Myocardial Infarction
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Reviewed by Dat Tien Nguyen, B.A, ScM.
Translated by Nhi Phuong Quynh Le, B.A |
Posted on December 10th, 2025
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Beta blockers have long been prescribed to prevent recurrent myocardial infarction, largely because of their antiarrhythmic properties. However, much of the evidence supporting this practice comes from studies conducted more than 40 years ago-before the widespread use of contemporary coronary reperfusion therapy. Their benefit in patients with preserved or mildly reduced left ventricular ejection fraction also remains uncertain. To address this gap, a government-funded study in Norway evaluated the effectiveness of beta blockers in a modern clinical context.
The trial was conducted in Norway and Denmark and included 5574 participants with a median age of 63 years. All had a prior myocardial infarction and an ejection fraction above 40%; none had a diagnosis of heart failure. During their index hospitalization, 92% underwent percutaneous coronary intervention, 2% had coronary-artery bypass grafting, and about 6% received no revascularization. At discharge, roughly 90% were prescribed aspirin, a statin, and a P2Y12 inhibitor.
Participants were randomized to receive long-acting metoprolol or no beta-blocker therapy. The median starting dose was 50 mg. The control group did not receive placebo. After a median follow-up of 3.5 years, treatment with a beta blocker was associated with a 15% lower risk of death or major cardiovascular events. The risk of recurrent myocardial infarction was reduced by 27%, whereas the risks of ischemic stroke and heart failure did not differ significantly between groups.
Other contemporary studies examining the preventive effects of beta blockers in similar clinical scenarios have not demonstrated benefits of this magnitude. Further research is therefore needed to clarify the role of beta blockers in patients without reduced ejection fraction. Future trials should address limitations of the current study, including its open-label design, the under-representation of women (only 20% of participants were female), and its focus on a single beta-blocker rather than evaluating other agents in the class.
The trial was conducted in Norway and Denmark and included 5574 participants with a median age of 63 years. All had a prior myocardial infarction and an ejection fraction above 40%; none had a diagnosis of heart failure. During their index hospitalization, 92% underwent percutaneous coronary intervention, 2% had coronary-artery bypass grafting, and about 6% received no revascularization. At discharge, roughly 90% were prescribed aspirin, a statin, and a P2Y12 inhibitor.
Participants were randomized to receive long-acting metoprolol or no beta-blocker therapy. The median starting dose was 50 mg. The control group did not receive placebo. After a median follow-up of 3.5 years, treatment with a beta blocker was associated with a 15% lower risk of death or major cardiovascular events. The risk of recurrent myocardial infarction was reduced by 27%, whereas the risks of ischemic stroke and heart failure did not differ significantly between groups.
Other contemporary studies examining the preventive effects of beta blockers in similar clinical scenarios have not demonstrated benefits of this magnitude. Further research is therefore needed to clarify the role of beta blockers in patients without reduced ejection fraction. Future trials should address limitations of the current study, including its open-label design, the under-representation of women (only 20% of participants were female), and its focus on a single beta-blocker rather than evaluating other agents in the class.