BACKGROUND: Many stable patients with chronic coronary syndrome continue ß-blocker therapy for years after a myocardial infarction, despite having no clear ongoing indication. Whether ß-blockers can be safely discontinued in such patients remains uncertain. The objective of this analysis was to assess the non-inferiority of ß-blocker discontinuation versus continuation in patients with previous myocardial infarction and no remaining indication.
METHODS: We performed a pooled analysis of individual patient data from the ABYSS and SMART-DECISION randomised trials in stable patients over 6 months after a myocardial infarction with a left ventricular ejection fraction of =40% and no heart failure. Non-inferiority was assessed for the composite primary endpoint of all-cause death, myocardial infarction, stroke, or hospitalisation for cardiovascular reasons, and for the key secondary endpoint of all-cause death, myocardial infarction, or hospitalisation for heart failure. Analyses used a one-stage mixed-effects Cox proportional hazards model including trial as a random effect with margins of 1·25 for the primary endpoint and 1·40 for the key secondary endpoint. The review protocol was registered with PROSPERO, number CRD420261299839.
FINDINGS: Among 6238 patients (3698 from ABYSS and 2540 from SMART-DECISION), 3092 were assigned to ß-blocker discontinuation and 3146 to continuation. Median time from index myocardial infarction to randomisation was 3·6 years (IQR 1·6-7·5) and median follow-up was 3·0 years (2·3-3·8). The primary endpoint occurred in 532 (17·2%) of 3092 patients in the ß-blocker discontinuation group and 500 (15·9%) of 3146 in the continuation group (hazard ratio 1·09 [95% CI 0·97-1·24]; pnon-inferiority=0·016). The key secondary endpoint occurred in 201 (6·5%) of 3092 patients in the discontinuation group and 201 (6·4%) of 3146 patients in the continuation group (1·01 [0·83-1·23]; pnon-inferiority=0·0006). Findings were consistent irrespective of background left ventricular ejection fraction.
INTERPRETATION: In stable patients with previous myocardial infarction, left ventricular ejection fraction =40%, no heart failure, and no other indication for ß-blocker therapy, discontinuation met the non-inferiority criteria for the primary and key secondary endpoints. Interpretation of the primary endpoint is limited by its hospitalisation-heavy and trial-dependent composition.
FUNDING: None.
| Discipline Area | Score |
|---|---|
| Internal Medicine |  |
| Cardiology | |
This is an interesting and relevant practice-changing paper in cardiology. For many years, guidelines recommended beta blockers for all patients with AMI without strong supporting evidence. With this trial and evidence from the REBOOT trial, now we know that not all patients need these therapies.
