Using beta blockers does not benefit patients who have survived a heart attack with normal cardiac function, according to a new study

This meta-analysis uses rigorous methodology to analyse the results of five recent studies on treatment with beta-blockers in patients after acute myocardial infarction (AMI) with preserved ejection fraction.

It complements previous information and highlights the results of the REBOOT clinical trial. Beta-blockers do not provide any benefit in this specific group of patients, i.e., those with preserved ejection fraction after AMI. Unlike REBOOT, a new finding is that women do not experience adverse effects when analysing the five trials.

The message should be that beta-blockers should not be discontinued in all patients without consulting a specialist. The patient's condition must be confirmed, and it must also be taken into account that beta-blockers may be taken for other indications such as high blood pressure or arrhythmias.

Therefore, the need for beta-blockers in post-AMI patients with preserved ejection fraction must be assessed with a medical specialist.

Is the study based on sound data and methods?

‘Yes. It is currently the most solid data available.’

What new information does it provide?

"In previous studies, there were some results that might seem contradictory. However, when this meta-analysis is carried out and the patients from the other four studies are added, the results are consistent and demonstrate the absence of benefit from beta-blockers in terms of mortality, reinfarction, or hospitalisation for heart failure in patients who have survived a myocardial infarction and have an ejection fraction greater than 50%."

Are there any important limitations to consider?

“All studies have limitations when it comes to applying their results to specific individuals. However, these limitations, recognised by the authors in the various studies, do not diminish the value of their conclusions when applied to the general population.”

How relevant is this study to clinical practice?

"The relevance is very important for clinical practice because, until now, it was believed that all patients who had survived a myocardial infarction, even if the infarction had not caused much damage to their heart, should take beta-blockers for life. Now it has been shown that this is not 'mandatory'. What happened until now? Did beta-blockers kill them or cause them to have another heart attack or be admitted to hospital more often? Not at all. But in some patients, beta-blockers could somewhat impair their quality of life by causing fatigue, worsening their lung problems, sleep or sexual function. However, there is also another group of patients who tolerate beta blockers very well or who may even feel better when taking them because they have better control of their heart rate, blood pressure, arrhythmias or even the way their heart feels."

What recommendations can be made based on this and other studies?

"The main recommendation is that beta blockers should not be recommended for all patients who suffer an acute myocardial infarction in which their heart has not suffered significant damage, as reflected in an ejection fraction of more than 50%."

Will this study have an impact on clinical practice guidelines, as indicated in the press release?

"Yes, because, fortunately, in cardiology we have clinical guidelines that provide guidance to doctors on treatments that have been proven effective in different pathologies. The recommendations are graded based on the available scientific evidence. We now have this new, very solid evidence that debunks the beliefs derived from previous studies and will therefore lead to changes in these clinical guidelines."

These data, based on a sample of nearly 18,000 patients, confirm what many of us have suspected for some time and clarify doubts raised by seemingly disparate results from recent trials. It confirms that beta-blockers have no role in patients with myocardial infarction with preserved left ventricular ejection fraction. It is important to note that, with the expansion of revascularisation strategies, most patients with myocardial infarction have this preserved ejection fraction and therefore do not require this therapy, unless they have another clinical indication for beta-blockade. The message for patients is that, after a heart attack, if their heart is not weak, beta-blockers are not indicated.