aTranta — Beta blockers are a mainstay of cardiovascular treatment and are often given to patients after a heart attack. But a new large-scale trial challenges that conventional wisdom and suggests the drug may not actually be helping many of these patients.

The trial enrolled about 5,000 patients whose ejection fraction had been particularly preserved after a heart attack, and the results, published here Sunday, showed that long-term treatment with beta-blockers was associated with fewer deaths or new heart attacks. It was found that the combined risk was not significantly reduced. Presented at the American College of Cardiology meeting and published in the New England Journal of Medicine.

Ejection fraction is the rate of blood that is forced out of the heart’s left ventricle with each heartbeat and serves as a measure of the heart’s squeezing ability. This study defined preserved or normal ejection fraction as 50% or higher, whereas other studies have defined it as 40% or higher.

The frequent use of beta-blockers after a heart attack is based on research conducted decades before advances in the procedures doctors now use to open blocked arteries. This drug is intended to slow the heartbeat and reduce stress on the heart, but it can cause side effects such as fatigue, weight gain, and sexual dysfunction.

These days, doctors question whether current guidelines recommending the use of beta-blockers regardless of ejection fraction still make sense, as patients’ heart attacks are smaller and cause less damage to the heart. ing. Observational studies suggest that beta-blockers may not be helpful in people with preserved ejection fraction, but the field has so far seen no large randomized trials that have examined this issue. was in short supply.

“This is one of the studies at ACC that I think has the potential to change medicine,” said Kim Eagle, director of the University of Michigan Frankel Heart and Vascular Center, who was not involved in the trial. This is “a very important breakthrough study that will change the way patients are managed today.” [heart attacks] being taken care of. ”

The trial enrolled mainly patients from Sweden, but also some patients from Estonia and New Zealand. Researchers followed patients for a median of three and a half years.

Patients assigned a beta-blocker had a 4% lower composite risk of death or new heart attack compared with those who did not take the drug, but this result was not statistically significant.

Additionally, people taking beta-blockers had a significantly lower risk for each of the individual outcomes studied: death from any cause, death from cardiovascular disease, heart attack, hospitalization for atrial fibrillation, and hospitalization for heart failure. It wasn’t low.

The incidence of events investigated for safety (e.g., stroke, hypotension, syncope) was similar between the two groups.

Researchers found that a subgroup of people who were already taking a beta-blocker when they had a heart attack and who were subsequently assigned to take a beta-blocker in the trial had an increased risk of death or new heart attacks. However, the authors stated that this is likely. False discovery.

“This is just a subgroup analysis without statistical power, and our study has no plausible explanation. This is why we believe this is a play of chance,” said the first author. , and interventional cardiac specialist at Lund University in Sweden, says: I said in an email.

It was not a blinded study, as patients not taking beta-blockers were not given a placebo drug. While that may have introduced some bias, the authors said it was unlikely to have influenced the difficult outcomes studied, such as death, heart attack and hospitalization.

Additionally, Anuradha Lara Trindad, an advanced heart failure and transplant cardiologist at Mount Sinai in New York who was not involved in the trial, said that given that the study enrolled primarily Swedish patients, He stated that there are limits to the generalizability of

Furthermore, only 22.5% of study participants were women. Historically, women have been underrepresented in cardiovascular disease clinical trials. “Our study includes a similar proportion of female patients as other comparable materials,” lead author Indigen said.

Although it remains to be seen how medical associations and guideline makers will react, Lara Trindade said, “It takes courage to question old dogma, so I commend the authors and the researchers.” “We’re in a very different time and we have a very different patient population, so it really raises the question of what do we continue to accept and what do we have to retest?”

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