The long-term utility of beta-blockers following an uncomplicated myocardial infarction (MI) remains a subject of clinical debate. New secondary results from the AβYSS trial (Assessment of β-blocker interruption one Year after an uncomplicated myocardial infarction on Safety and Symptomatic cardiac events requiring hospitalization) reveal that interrupting this therapy leads to sustained increases in blood pressure (BP) and heart rate (HR), with potentially adverse clinical outcomes, particularly in patients with a history of hypertension.¹

AβYSS was a multicentre, randomised, open-label trial conducted across 49 sites in France. The study enrolled 3,698 stable patients who had experienced an MI at least six months prior and had a preserved left ventricular ejection fraction (LVEF >40%). Participants were randomised to either interrupt or continue their beta-blocker therapy. This analysis focused on the haemodynamic effects (changes in BP and HR) and the clinical outcomes in pre-specified subgroups of patients with or without a history of hypertension over a median follow-up of 3.0 years. The primary endpoint of the main trial was a composite of all-cause death, non-fatal MI, non-fatal stroke, or hospitalisation for a cardiovascular reason.²

At six months, patients in the beta-blocker interruption group experienced significant increases from baseline compared to the continuation group. This included a rise in systolic BP of +3.7 mmHg (95% CI [2.6, 4.8]; p<0.001), diastolic BP of +3.3 mmHg (95% CI [2.6, 4.0]; p<0.001), and resting HR of +10 bpm (95% CI [9, 11]; p<0.001). These haemodynamic changes were sustained throughout the follow-up period, despite more frequent prescription of other antihypertensive medications in the interruption arm.

A history of hypertension was present in 43% of the cohort, and these patients were found to be at a higher overall risk for the primary composite endpoint compared to non-hypertensive patients (25.8% vs 19.2%; adjusted hazard ratio [aHR] 1.18, 95% CI [1.01–1.36]; p=0.03). In this higher-risk hypertensive subgroup, interrupting beta-blocker therapy was associated with a marked increase in the primary endpoint (risk difference 5.02%; aHR 1.23, 95% CI [1.01–1.50]; p=0.04).

These findings from the AβYSS trial suggest that the haemodynamic benefits of beta-blockers, specifically the control of BP and HR, are crucial for long-term stability in post-MI patients, even those considered uncomplicated. The loss of this control upon interruption may directly contribute to poorer clinical outcomes. The AβYSS Investigators concluded, "Interruption of β-blocker treatment after an uncomplicated MI led to a sustained increase in BP and HR, with potentially deleterious effects on outcomes, especially in patients with history of hypertension."¹ The results underscore the need for caution when considering the discontinuation of beta-blockers, particularly in the substantial subset of post-MI patients who also have hypertension.

The investigators noted that further randomised trials are needed to confirm these findings and should include careful monitoring of BP, HR, and hospitalisation rates to fully elucidate the long-term impact of beta-blocker interruption.

References

1. Procopi N, Zeitouni M, Kerneis M, et al. Beta-blocker interruption effects on blood pressure and heart rate after myocardial infarction: the AβYSS trial. Eur Heart J. 2025;46(29):2894–2902. https://doi.org/10.1093/eurheartj/ehaf170

2. Silvain J, Cayla G, Ferrari E, et al. Beta-blocker interruption or continuation after myocardial infarction. N Engl J Med. 2024;391:1277–86. https://doi.org/10.1056/NEJMoa2404204

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