Beta-blocker therapy and sexual dysfunction after myocardial infarction: a sub-study of the BETAMI-DANBLOCK trial

Background Sexual dysfunction is common after myocardial infarction (MI), but the role of beta-blockers on these disturbances remains unclear. Purpose To evaluate the presence of beta-blocker induced sexual dysfunction in post-MI patients without a reduced left ventricular ejection fraction (LVEF ≥40%) enrolled in the BETAMI-DANBLOCK trial. Methods A prespecified analysis of data from BETAMI-DANBLOCK which randomly assigned patients with a recent MI and an LVEF ≥40% to open-label beta-blocker therapy (median treatment dose metoprolol 50mg/day) or no beta-blocker therapy. For patients reporting sexual activity within the past 12 months, sexual function during the past 4 weeks was assessed at baseline and follow-up (3, 12, and 21 months) with the 5-item International Index of Erectile Function (IIEF, men) and the 6-item Female Sexual Function Index (FSFI, women). Sum scores for IIEF (range 5–25) and FSFI (6–30) provides measures of sexual function increasing with higher sexual function; thresholds for dysfunction were IIEF ≤21 and FSFI ≤19. Beta-blocker effects on IIEF and FSFI scores were analysed as between-group differences in change using linear mixed models (negative estimates indicating worse sexual function with beta-blockers). Odds ratios (ORs) for sexual dysfunction were estimated with multivariable logistic regression adjusting for randomisation stratification variables LVEF and study site. Results Among 5574 patients in BETAMI-DANBLOCK, 2850 stated sexual activity within past year at baseline. Of these, 2332/2850 (82%) responded to IIEF or FSFI at least once during the trial period. Among men, baseline median IIEF score was 23 (IQR: 19-24) in the beta-blocker group and 23 (IQR: 19-25) in the no beta-blocker group, with 39% reporting scores indicating erectile dysfunction and 12% in DANBLOCK dispensing sildenafil. We found no statistically significant effect of beta-blockers on the total IIEF score during follow-up (Table). However, the odds of erectile dysfunction was slightly higher in the beta-blocker group at the first follow-up (3 months OR: 1.58, 95% CI: 1.02, 2.42), but not on the subsequent timepoints. The proportion of filled sildenafil prescriptions was similar in the beta-blocker and no beta-blocker group (18% vs 17%) during follow-up in DANBLOCK. Among women, median FSFI score at baseline was 24 (IQR: 20-27) and 24 (IQR: 18-27), with 24% and 31% of patients having a score indicating sexual dysfunction for the beta-blocker group and the no beta-blocker group, respectively. We found no effect of beta-blocker therapy on FSFI scores during follow-up, but effect estimates were uncertain. Conclusions In the BETAMI-DANBLOCK trial, beta-blocker therapy after MI was associated with a small transient increase in erectile dysfunction among men, but no long-term effects were observed.