Sex differences in leadless pacemaker implantation: a propensity matched analysis from i-LEAPER registry

Background: The impact of sex in clinical and procedural outcomes in leadless pacemakers (LPMs) patients has not been investigated yet. Objective: To investigate sex-related differences in patients undergoing LPMs implantation. Methods: Consecutive patients enrolled in the i-LEAPER registry were analyzed. Comparisons between sexes were performed within the overall cohort and using an adjusted analysis with 1:1 propensity-matching for age and comorbidities. The primary outcome was the comparison of major complication rates; sex-related differences regarding electrical performance and all-cause mortality during follow-up were deemed secondary outcomes. Results: In the overall population (n=1179 patients; median age 80 years), 64.3% were men. After propensity-matching, 738 patients with no significant baseline differences among groups were identified. During a median follow-up of 25 (interquartile range [IQR] 24-39) months, female sex was not associated with LPM-related major complications (hazard ratio [HR] 2.03, 95% confidence interval [CI] 0.70-5.84, p=0.190) and with all-cause mortality (HR 0.98, 95% CI 0.40-2.42, p=0.960). LPM electrical performance resulting comparable between groups, excepting for a higher pacing impedance in women at implant and during follow-up (24-month: 670 [550-800] vs 616 [530-770] ohms, p=0.014), however remaining within normal limits. Conclusions: In a real-world setting, we found differences in sex-related referral patterns for LPM implantation with an under-representation of women, although major complication rate, and LPM performances were comparable between sexes. Female patients showed higher impedance values, not showing any impact on the overall device performance. Electrical parameters remained within normal limits in both groups during the entirety of follow-up.