ABYSS: Can beta-blocker safely be interrupted post-MI?

Beta-blocker interruption after a myocardial infarction (MI) failed to meet non-inferiority criteria in the ABYSS trial. Discontinuation resulted in higher hospitalisation rates among patients with MI and a preserved left ventricular ejection fraction (LVEF) compared with continued treatment with a beta-blocker, particularly in patients with hypertension. Furthermore, no quality-of-life improvements were reported in the beta-blocker interruption arm.

The phase 3, open-label, non-inferiority ABYSS trial (NCT03498066) randomised 3,698 stabilised patients with a history of MI and a preserved LVEF (≥40%) 1:1 to beta-blocker interruption or continued treatment to assess the safety and effect on quality-of-life of the interruption strategy [1,2]. The primary endpoint was a composite of death, MI, stroke, or hospitalisation for cardiovascular reasons, with a minimal follow-up of 1 year.

After a median follow-up of 3.0 years, participants in the interruption arm had a slightly increased risk of experiencing a primary outcome event than participants in the continuation arm (23.8% vs 21.1%; HR 1.16; 95% CI 1.01–1.33; P_{non-inferiority}=0.44). “This effect was driven by an increase in hospitalisations for cardiovascular reasons [18.9% vs 16.6%],” explained Prof. Johanne Silvain (Pitié-Salpêtrière University Hospital, France).

Next, the authors observed no difference in quality-of-life scores between the 2 treatment arms, as measured by the EQ-5D-5L score. However, they did note that participants in the interruption arm had significantly higher systolic blood pressure (+3.7%) and diastolic blood pressure (+3.9%) at 6 months than those in the continuation arm. Similarly, the interruption strategy significantly increased the heart rate of these participants with a mean of 9.8 bpm (P<0.001) compared with baseline.

In short, the ABYSS trial showed that beta-blocker interruption was not as safe as beta-blocker continuation, leading to a higher rate of hospitalisations among patients with MI and a preserved LVEF. Prof. Silvain added that these results need to be contextualised with recent findings from the REDUCE-AMI trial and ongoing trials on the optimal use of beta-blockers after MI.

Relevant reading:

• REDUCE-AMI: Re-evaluating the role of routine beta-blockade in patients with acute myocardial infarction (ACC 2024)

 

1. 
   
   1. Silvain J, et al. N Engl J Med 2024;391:1277-1286.
   2. Silvain J, et al. Assessment of Beta blocker interruption one year after an uncomplicated myocardial infarction on safety and symptomatic cardiac events requiring hospitalisation. HOTLINE 1, ESC Congress 2024, 30 Aug–02 Sept, London, UK.

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Posted on 7 November 20247 November 2024