Comparison of Procedure and Fluoroscopy Time Between Left Bundle Branch Area Pacing and Right Ventricular Pacing for Bradycardia: The Learning Curve for the Novel Pacing Strategy.

Background: Left bundle branch area pacing (LBBAP) is a novel physiological pacing approach. Objective: To assess learning curve for LBBAP and compare the procedure and fluoroscopy time between LBBAP and right ventricular pacing (RVP). Methods: Consecutive bradycardia patients who underwent LBBAP or RVP were prospectively recruited from June 2018 to June 2020. The procedure and fluoroscopy time for ventricular lead placement, pacing parameters, and periprocedural complications were recorded. Restricted cubic splines were used to fit learning curves for LBBAP. Results: Left bundle branch area pacing was successful in 376 of 406 (92.6%) patients while 313 patients received RVP. Learning curve for LBBAP illustrated initial (1-50 cases), improved (51-150 cases), and stable stages (151-406 cases) with gradually increased success rates (88.0 vs. 90.0 vs. 94.5%, P = 0.106), steeply decreased median procedure (26.5 vs. 14.0 vs. 9.0min, P < 0.001) and fluoroscopy time (16.0 vs. 6.0 vs. 4.0min, P < 0.001), and shortened stimulus to left ventricular activation time (Sti-LVAT; 78.7 vs. 78.1 vs. 71.2 ms, P < 0.001). LBBAP at the stable stage showed longer but close median procedure (9.0 vs. 6.9min, P < 0.001) and fluoroscopy time (4.0 vs. 2.8min, P < 0.001) compared with RVP. Conclusion: The procedure and fluoroscopy time of LBBAP could be reduced significantly with increasing procedure volume and close to that of RVP for an experienced operator.