His Bundle Pacing: Predicting Mortality and Major Complications in Mid-Term Follow-Up.

Introduction : His bundle pacing (HBP) is suitable for 80% of patients with any indication for permanent pacemaker implantation, with a clinical benefit compared to right ventricular pacing (RVP). Although complications and mortality related to RVP are widely reported in the literature, data on HBP are limited. This study aimed to analyze HBP complications and outcomes in the short-term (up to 30 days) and long-term (up to the following 24 months) follow-up (F/U). Materials and Methods : The study includes 373 patients aged ≥ 18, enrolled from October 2015 to May 2019 in a single-center HBP prospective registry conducted in the Department of Electrocardiology, Upper Silesian Medical Centre of the Medical University of Silesia in Katowice, Poland. Mortality and HBP complications were used as end-points: during hospitalization and up to 30 days (short-term F/U), and for each F/U point-six months, 12 months, and 24 months after the procedure (long-term F/U). Results : Successful HBP was achieved in 252 patients (68%), with an increasing success rate during consecutive years: 57% in 2015-2016 and 73% in 2017-2019. Complications were found in 8.4% of patients (21/252) in short-term F/U and 5.8% (13/224), 5.5% (11/201), and 6.9% (12/174) at six months, 12 months, and 24 months, respectively. There were no deaths during the first 30 days. However, 26 patients (10.3%) died within 24 months. A left ventricular ejection fraction (LVEF) ≤ 34% was the only independent predictor of all-cause mortality or any major complication in the 24-month F/U. Conclusions : This single-center study reported a low risk of mortality and complications associated with HBP at the short-term F/U. However, during the long-term F/U, we observed a higher but acceptable risk of major complications, with a lower LVEF being an independent predictor of the composite end-point of all-cause mortality or any major complication.