His bundle pacing and left bundle branch area pacing: Feasibility and safety.

Introduction And Objectives: There has been increasing interest in pacing methods that provide physiological stimulation, such as His bundle pacing (HBP) or left bundle branch area pacing (LBBAP). Our goal was to assess the feasibility and safety of these techniques.

Methods: Prospective observational single-center study evaluating 46 patients with indication for a pacemaker that attempted HBP or LBBAP from July 2020 to November 2021. Procedural endpoints and pacing parameters were assessed and compared at implantation and three-month follow-up.

Results: Overall acute procedural success was achieved in 96% of the cases. Successful HBP was achieved in 91% of the patients and all patients for LBBAP. During implantation, HBP patients presented a higher capture threshold (0.80 [0.55-1.53] V vs. 0.70 [0.40-0.90] V, p=0.08) and lower R-wave amplitude (4.0 [2.9-6.2] mV vs. 7.8 [5.5-10.5] mV, p=0.001) compared to LBBAP patients. There was no difference between groups, either acutely or at 3-months, regarding paced QRS duration (125±22 ms vs. 133±16 ms, p=0.08; 118±16 ms vs. 124±14 ms, p=0.19). Although procedural time was similar with both techniques (95 [75-139] min vs. 95 [74-116] min, p=0.79), fluoroscopy time was significantly reduced during LBBAP (8.1 [5.3-13.4] min vs. 4.1 [3.1-11.3] min, p=0.05). At 3 months of follow-up, the pacing threshold remained with a stable profile in HBP as in LBBAP (1.25 [0.75-2.00] V, p=0.09 and 0.60 [0.50-0.80] V, p=0.78), respectively. The need for re-intervention occurred in 3 (6.5%) HBP cases during follow-up.

Conclusion: This first national study demonstrates the feasibility and safety of the HBP and LBBAP in patients with pacemaker indication.