After a heart attack, atenolol tracked with fewer events than bisoprolol

Among people who had a heart attack but no sign of heart failure, those started on atenolol had fewer major cardiovascular events over the next two years than those started on bisoprolol, in a French study of 11,558 patients [s1]. The study is observational, drawn from insurance records rather than a randomised trial, so it can show an association but cannot prove that one beta-blocker causes better outcomes than the other [s1].

That caveat is the whole story here, and it should sit next to the headline result rather than below it.

Why the question is open

Beta-blockers are a long-standing part of care after a heart attack, and treatment guidelines recommend them [s1]. But "a beta-blocker" is not one drug. Atenolol and bisoprolol are both selective beta-blockers used for the same indications, and they have rarely been compared head-to-head after a heart attack, so which specific agent to reach for has been more a matter of habit and local practice than of evidence [s1].

The ground beneath the whole class has also shifted. The randomised REDUCE-AMI trial found no benefit from routine beta-blockers after a heart attack in patients whose heart pumping function was preserved, raising the prior question of whether many such patients need one at all [s2]. This site has covered the case for stopping beta-blockers long after a heart attack and a meta-analysis in patients with preserved ejection fraction. The new study asks a narrower question: among patients who are prescribed one, does the choice of agent matter?

How it was done

Researchers used the French National Health Data System, a national administrative database [s1]. They identified patients aged 18 or older who were hospitalised in the Paris area between 1 January 2008 and 31 December 2018 with a new heart attack and were dispensed either atenolol or bisoprolol within two days of discharge [s1]. Patients who had already been taking a beta-blocker or a loop diuretic, or who had a recorded diagnosis of heart failure in the preceding two years, were excluded — an attempt to strip out people whose beta-blocker was really being prescribed for heart failure [s1].

Outcomes were tracked for up to two years [s1]. The primary outcome was a composite of major adverse cardiovascular events — cardiac arrest, death from any cause, reinfarction, stroke, or hospitalisation for heart failure — and the secondary outcome was death from any cause [s1]. The analysis used a causal-inference method called targeted maximum likelihood estimation to estimate the average treatment effect of starting atenolol rather than bisoprolol [s1].

What it found

Of the 11,558 patients, 1,523 (13.2%) were started on atenolol and 10,035 (86.8%) on bisoprolol within two days of discharge [s1]. Comparing the atenolol group with the bisoprolol group, the average treatment effect was 2.9 percentage points (95% confidence interval, 1.1 to 4.7) for major adverse cardiovascular events, in atenolol's favour [s1]. In weighted terms, 10.8% of the atenolol group and 14.1% of the bisoprolol group had a major cardiovascular event [s1].

For death from any cause, the difference was smaller and not statistically significant: an average treatment effect of 0.6 percentage points (95% CI, -0.2 to 1.3), with weighted mortality of 1.4% on atenolol and 2.2% on bisoprolol [s1]. So the signal is in the composite of cardiovascular events, not clearly in survival.

What it does and does not establish

The authors are careful, and the limitation is fundamental: this is an association between the drug a patient happened to be started on and their later outcomes, not the result of random assignment [s1]. Doctors chose atenolol or bisoprolol for reasons the database cannot fully capture, and bisoprolol was prescribed roughly six times as often, so the two groups may have differed in ways that also affect outcomes — the classic problem of confounding by indication. The exclusion of heart failure relied on diagnosis codes and dispensed loop diuretics, which will miss some cases, and the data came from a single region over one decade [s1]. The causal-inference method adjusts for measured differences, but it cannot adjust for what was never recorded.

What the study does provide is a well-sized, real-world signal that the choice of beta-blocker after a heart attack may not be interchangeable, and a specific, testable hypothesis: that atenolol is at least as good as bisoprolol in patients without heart failure [s1]. That is the kind of question a randomised trial could settle cleanly, and this study is an argument for running one rather than an answer in itself.

What to watch

Guidelines currently recommend beta-blockers after a heart attack without specifying which one, and a single observational study will not change that [s1]. The result is worth watching precisely because head-to-head drug comparisons are so rarely funded; whether anyone mounts a randomised test of atenolol versus bisoprolol is the open question.

This article describes research findings. It is not medical advice, and nothing here should be used to start, stop or switch a medication.

Sources

• Atenolol or Bisoprolol after Myocardial Infarction without Recorded Heart Failure, NEJM Evidence, 22 September 2026
• Beta-Blockers after Myocardial Infarction and Preserved Ejection Fraction (REDUCE-AMI), New England Journal of Medicine, 7 April 2024