Impact of beta-blockers on quality of life in patients with myocardial infarction without heart failure: a sub-study of the DANBLOCK-trial

Abstract Background Diagnosis and treatment of myocardial infarction (MI) have advanced substantially since the early beta-blocker trials of the 1980s. Although recent meta-analyses suggest continued cardioprotective effects in patients with mildly reduced left ventricular ejection fraction (LVEF 40–49%) and no heart failure, evidence on patient-reported outcomes remains limited. Purpose To evaluate the effect of beta-blockers on quality of life after MI in patients without heart failure and with mildly reduced (40–49%) or preserved LVEF (≥50%). Methods This was a prespecified substudy of the randomized, controlled, open-label DANBLOCK trial. A total of 2707 patients with recent MI (≤14 days) and LVEF 40% were enrolled at 25 hospitals (2018–2024) and randomized 1:1 to beta-blocker therapy or no beta-blocker therapy. The primary endpoint was change in health-related quality of life, assessed using EQ-5D-5L and EQ visual analogue scale (VAS) at baseline and three, 12, and 24 months. Analyses were performed using linear mixed-effects models including an interaction between treatment and time, adjusted for LVEF 50%. Results are reported as estimated mean differences with 95% confidence intervals. Analyses were conducted in the intention-to-treat population. Results Among 2707 randomized patients (median age 62 years, 21% women), 2681 (99%) completed at least one EQ-5D assessment. Baseline characteristics were well balanced between groups. Median baseline EQ-5D index score was 0.95 (IQR 0.86–1.00) in both groups and remained stable throughout follow-up. A significant improvement on the EQ-5D mean index-score was observed from baseline to three and 12 months follow-up. The linear mixed-effects model showed no significant differences in change of EQ-5D index score between beta-blocker and no beta-blocker groups at 3 months (mean difference –0.002 95% CI –0.016 to 0.013, p=0.81), 12 months (–0.001 –0.016 to 0.013, p=0.86), or 24 months (0.010 –0.006 to 0.026, p=0.21). Median EQ VAS scores ranged from 76 to 79 (IQR 65-88) across all time points, with no significant between-group differences indicating a stable self-percieved health over time. In the mixed-effects model, no statistically significant differences in the mean EQ VAS score were observed between the groups at any time point, with an estimated difference of 1.20 (95%CI; -2.72, 0.32, p=0.12) at three months, -1.35 (95%CI; -2.85, 0.15, p=0.08) at 12 months and -0.64 (95%CI; -2.28, 1.00, p=0.443) at 24 months. Sensitivity analyses confirmed these findings. EQ-5D index-scores among subgroups were consistent. Conclusion In this pre-specified substudy of the DANBLOCK-trial, beta-blocker therapy did not affect quality of life after MI in patients without heart failure, supporting its safe use in this population.For image description, please refer to the figure legend and surrounding text. For image description, please refer to the figure legend and surrounding text.