A single-center experience with early adoption of physiologic pacing approaches

Background: Increasing interest in physiological pacing has been countered with challenges such as accurate lead deployment and increasing pacing thresholds with His-bundle pacing (HBP). More recently, left bundle branch area pacing (LBBAP) has emerged as an alternative approach to physiologic pacing. Objective: To compare procedural outcomes and pacing parameters at follow-up during initial adoption of HBP and LBBAP at a single center. Methods: Retrospective review, from September 2016 to January 2020, identified the first 50 patients each who underwent successful HBP or LBBAP. Pacing parameters were then assessed at first follow-up after implantation and after approximately 1 year, evaluating for acceptable pacing parameters defined as sensing R-wave amplitude >5 mV, threshold <2.5 V @ 0.5 ms, and impedance between 400 and 1200 Ω. Results: The HBP group was younger with lower ejection fraction compared to LBBAP (73.2 ± 15.3 vs. 78.2 ± 9.2 years, p =.047; 51.0 ± 15.9% vs. 57.0 ± 13.1%, p =.044). Post-procedural QRS widths were similarly narrow (119.8 ± 21.2 vs. 116.7 ± 15.2 ms; p =.443) in both groups. Significantly fewer patients with HBP met the outcome for acceptable pacing parameters at initial follow-up (56.0% vs. 96.4%, p =.001) and most recent follow-up (60.7% vs. 94.9%, p ≤.001; at 399 ± 259 vs. 228 ± 124 days, p ≤.001). More HBP patients required lead revision due to early battery depletion or concern for pacing failure (0% vs. 13.3%, at a mean of 664 days). Conclusion: During initial adoption, HBP is associated with a significantly higher frequency of unacceptable pacing parameters, energy consumption, and lead revisions compared with LBBAP.