Hot Line: Is long-term beta-blocker therapy needed after an MI?
31 Aug 2024
“Improvements in management and data from observational studies have led physicians to question whether continuing beta-blockers after 1 year post-myocardial infarction (MI) is needed since unnecessary treatment may result in side effects.1-4 We conducted the ABYSS trial to provide conclusive randomised data on the effects of beta-blocker interruption vs. continuation on CV events and quality of life (QoL),” said Professor Johanne Silvain (Sorbonne University - Paris, France) who presented the key findings yesterday.
The open-label, non-inferiority ABYSS trial, conducted by the ACTION Group in France, included patients with a prior MI taking long-term beta-blockers, with LVEF ≥40% and no CV events in the previous 6 months. Participants were randomised to interrupting or continuing their beta-blocker medication. The primary endpoint was a composite of death, non-fatal MI, non-fatal stroke or hospitalisation for cardiovascular reasons at the longest follow-up (minimum, 1 year), according to an analysis of non-inferiority (defined as a between-group absolute difference of <3 percentage points for the upper boundary of the two-sided 95% CI). The main secondary endpoint was the change in QoL as measured by the European Quality of Life–5 Dimensions questionnaire.
In total 3,698 patients were randomised, with a mean age of 64 years and 17% were female. The median time between last MI and randomisation was 2.9 years (IQR 1.2–6.4 years).
Over median follow-up of 3 years, interruption of long-term beta-blockers was not shown to be non-inferior to beta-blocker continuation.
A primary-outcome event occurred in 23.8% of patients in the interruption group and in 21.1% in the continuation group (risk difference 2.8 percentage points; 95% CI <0.1–5.5), with a hazard ratio of 1.16 (95% CI 1.01–1.33; p=0.44 for non-inferiority).
Death occurred in 4.1% in the interruption group and 4.0% in the continuation group, while MI occurred in 2.5% and 2.4%, respectively. Of note, hospitalisation for CV causes occurred in 18.9% in the interruption group and 16.6% in the continuation group. Beta-blocker interruption was also associated with increases in systolic and diastolic blood pressure and heart rate at 6 months (all p<0.001 vs. beta-blocker continuation) and during follow up. Beta-blocker interruption did not improve QoL.
Summing up the evidence, Prof. Silvain concluded: “Differences between the groups with respect to hospitalisation for CV reasons and the negative effect on blood pressure levels, together with the absence of QoL improvement do not support interruption of a chronic beta-blocker treatment in post-MI patients. These results must be put into context with recent findings from the open-label REDUCE-MI5 trial and ongoing trials to provide additional evidence on the optimal use of beta-blockers after MI.”
References
- Holt A, et al. Eur Heart J. 2021;42:907–914.
- Park CS, et al. Circ Cardiovasc Interv. 2021;14:e010159.
- Puymirat E, et al. BMJ. 2016;354:i4801.
- Kim J, et al. Eur Heart J. 2020;41:3521–3529.
- Yndigegn T, et al. N Engl J Med. 2024;390:1372–1381.
