Gender Differences for His Bundle Pacing Long-Term Performance in the Elderly Population.

Background and aims: His bundle pacing (HBP) is considered the most physiological form of cardiac pacing. Although feasibility studies have included older patients, specific data for HBP in this population are scarce. This study aimed to evaluate gender differences in HBP long-term performance in elderly patients with atrioventricular (AV) block.

Methods: This retrospective study included 73 patients aged over 65 years with successful HBP and at least 2 years of follow-up. The patients' baseline and follow-up clinical and procedural characteristics were recorded.

Results: The mean age of the cohort was 72.8 ± 6.3 years, with 43 males and 30 females. The paced QRS complex was significantly narrower than the baseline value for both genders. Females had a narrower-paced QRS complex without differences in detection, type of His bundle capture, impedance, or fluoroscopy time. The pacing threshold increased progressively, reaching statistical significance compared to the baseline values at the two-year follow-up. The pacing threshold increased by more than 1 V over the follow-up period in twenty-four patients (32.9%) and by more than 2 V in six patients (8.2%), with no significant difference between genders. The pacing threshold increase occurred within the first year for most patients, without gender differences. Multivariate Cox regression analysis demonstrated that the paced QRS duration, left ventricular ejection fraction, and ischemic cardiomyopathy were significantly associated with the pacing threshold increase over time.

Conclusion: In elderly patients with AV block, HBP remains a feasible pacing method, without significant gender differences, over a long-term follow-up period. Pacing threshold increases are expected in up to one-third of the patients, requiring regular follow-ups to adjust the programmed parameters and optimize battery longevity.