Effect of left bundle branch area pacing on cardiac remodeling and function: propensity score matching with right ventricular pacing.

BACKGROUND: Conventional right ventricular pacing (RVP) causes cardiac dyssynchrony, and increases risk of pacing-induced cardiomyopathy (PICM), heart failure hospitalization and mortality. Left bundle branch area pacing (LBBAP) is a promising physiological pacing modality, we compared the effect of LBBAP on cardiac function with RVP in patients with atrioventricular block (AVB). METHODS: A total of 118 patients with AVB who successfully underwent LBBAP were enrolled between June 2019 and June 2022. Among them, 110 patients with a baseline LVEF ≥ 50% were propensity-matched 1:1 with 49 patients who underwent RVP during the same period. Ultimately, 41 patients with well-matched baseline characteristics in both groups were included in the analysis. Echocardiographic parameters and NYHA classification at 1-year follow-up were compared between the groups. RESULTS: Left ventricular ejection fraction (LVEF) remained stable in patients with LVEF ≥ 50% (62.9 ± 2.9 vs. 62.9 ± 3.3, P = 0.960), and improved significantly in patients with LVEF < 50% (58.0 ± 9.9% vs. 44.2 ± 5.5%, P < 0.05) at 1-year follow-up in the LBBAP group. Propensity score matching for baseline characteristics yielded 41 matched pairs. Changes in LVEF and left ventricular end-diastolic diameter (LVEDD) in the LBBAP group were significantly different from those in the RVP group: LVEF [-2.8(-5.0, -0.6), P = 0.015] and LVEDD [1.3(0.1, 2.5), P = 0.036], respectively. Compared with baseline, NYHA classification improved significantly in the LBBAP group (1.3 ± 0.5 vs. 1.0 ± 0.2, P < 0.05), while remained changed in the RVP group (1.3 ± 0.4 vs. 1.1 ± 0.3, P = 0.232). LBBAP showed a tendency to reduce PICM compared with RVP (0% vs. 9.8%), though the difference was not significant (P = 0.124). CONCLUSIONS: LBBAP might be a preferable pacing modality to improve cardiac remodeling and function in patients requiring high ventricular pacing burden compared with conventional RVP.