New Evidence Challenges Widespread Prescription of Beta-Blockers for Heart Attack Patients

A new study suggests limitations of beta-blocker therapy for some heart attack patients.

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Beta-blockers have long been the go-to medication for treating heart attacks. However, a new study suggests these drugs may not benefit patients with otherwise normal cardiac function.

The findings challenge the widespread use of beta-blockers in the modern treatment of heart attacks, potentially signaling that this decades-old therapy may be ill-suited for some patients.

Trial Finds No Benefits from Beta-Blockers

The new study, which was published in the New England Journal of Medicine, followed over 5,000 patients who had recently undergone coronary angiography after a heart attack, reached a similar conclusion.

The participants, who were from Sweden, Estonia, and New Zealand, were randomly assigned to receive long-term beta-blocker therapy or no treatment. The study found that beta-blockers did not lower the cumulative incidence of outcomes such as all-cause mortality, cardiovascular mortality, recurrent heart attacks, or hospital admissions.

Moreover, those taking beta-blockers experienced slightly higher rates of adverse effects, including atrioventricular blocks, bradycardia, syncope, hypotension.

“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,” Dr. Troels Yndigegn, the study’s lead author, said in a press release. “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.”

However, some critics warn it is too early to completely abandon the go-to treatment.

“A critical axiom in evidence-based medicine is that ‘absence of evidence is not evidence of absence,’” Dr. Philippe Gabriel Steg, a professor of Cardiology at Université de Paris, wrote in an editorial. “Given the difficulty of unambiguously showing an absence of benefit with beta-blocker therapy and the limitations of a single, somewhat underpowered, open-label trial, it may be too early to cut beta-blockers from the ’secondary prevention team' definitively,” he added.

Past Research Also Questions the Cardiac Status Quo

A heart attack, also known as a myocardial infarction, occurs when there is insufficient blood flow to a portion of the heart muscle. This lack of blood flow is typically caused by a blockage in one or more of the heart’s arteries. Without adequate blood supply, the affected heart muscle starts to die, leading to permanent damage and potentially death.

Every year, over 800,000 Americans have a heart attack, most often because of coronary heart disease, the leading cause of death in the U.S.

Standard treatment for a heart attack includes a variety of medications, such as anti-clotting drugs, anti-arrhythmia medications, antihypertensives that treat hypertension, statins, and beta-blockers.

Beta-blockers work by slowing the heart rate, allowing the organ to recover from the injury caused by the heart attack. These drugs were first developed in the late 1950s.

Recent studies have questioned the efficacy of beta-blockers as the go-to medication for heart attack treatment.

A meta-analysis of 60 trials involving over 102,000 participants found that beta-blockers do not provided a mortality benefit (the difference in mortality between treated and untreated patients).

A 2014 meta-analysis concluded that “in contemporary practice of treatment of myocardial infarction, beta-blockers have no mortality benefit but reduce recurrent myocardial infarction and angina (short-term) at the expense of increase in heart failure, cardiogenic shock, and drug discontinuation.”