The ABYSS trial, presented at ESC Congress 2024, aimed to evaluate the cardiovascular safety and quality of life impact of interrupting beta-blocker treatment in patients with a history of myocardial infarction (MI). The trial, conducted by the ACTION Group, included patients taking long-term beta-blockers with a left ventricular ejection fraction of at least 40% and no cardiovascular events in the previous 6 months. Participants were randomized to interrupting or continuing their beta-blocker medication.
The primary endpoint of the trial was a composite of death, non-fatal MI, non-fatal stroke, or hospitalization for cardiovascular reasons at the longest follow-up (minimum, 1 year). Over a median follow-up of 3 years, interruption of long-term beta-blocker treatment was not shown to be non-inferior to beta-blocker continuation. The occurrence of primary outcome events was similar between the interruption and continuation groups, with a slightly higher risk of events in the interruption group.
Specifically, death, MI, and hospitalization for cardiovascular reasons occurred at similar rates in both groups, with a slight increase in these events in the interruption group. Additionally, interruption of beta-blocker treatment was associated with increases in systolic and diastolic blood pressure and heart rate at 6 months. These findings suggest that interrupting beta-blocker treatment in post-MI patients may not be beneficial in terms of cardiovascular safety and quality of life.
The results of the ABYSS trial do not support the interruption of chronic beta-blocker treatment in post-MI patients, as it did not demonstrate non-inferiority to beta-blocker continuation in terms of cardiovascular events. The trial also did not show any improvement in quality of life with beta-blocker interruption, indicating that the potential risks and negative effects may outweigh any benefits. These findings should be considered in conjunction with other recent trials investigating the optimal use of beta-blockers after MI.
Overall, the ABYSS trial highlighted the importance of continued beta-blocker treatment in post-MI patients for cardiovascular protection. The study’s findings contribute to the ongoing discussion among physicians regarding the necessity of long-term beta-blocker therapy in this patient population. Future research, including ongoing trials and additional evidence, is needed to further elucidate the optimal use of beta-blockers after MI and to inform clinical practice guidelines.