Overview

• The REBOOT randomized trial in Spain and Italy (n=8,505) found no reduction in all-cause death, reinfarction or heart failure hospitalization for patients with LVEF ≥40% managed invasively (HR 1.04; NEJM).
• A combined analysis of the BETAMI and DANBLOCK trials (n=5,574) reported fewer composite events with long-term beta-blockers in patients with LVEF ≥40% and no clinical heart failure (14.2% vs 16.3%; HR 0.85), driven by fewer new MIs.
• An individual-patient meta-analysis across four trials (n=1,885 with LVEF 40–49%) showed a significant benefit for beta-blockers in this mildly reduced EF subgroup (10.7% vs 14.4%; HR 0.75; The Lancet) with no heterogeneity across countries or trials.
• Across BETAMI–DANBLOCK, differences were not apparent for several individual outcomes such as heart failure or malignant arrhythmias, and REBOOT’s exploratory analyses signaled higher event rates in women on beta-blockers, though power was limited.
• Investigators cautioned that results should be integrated with other recent and ongoing studies, with further research needed for patients with preserved EF (>50%) before practice changes are considered.