Effectiveness and safety of upgrading to conduction system pacing compared with biventricular pacing in patients with pacing-induced cardiomyopathy: Results of a propensity score-matched analysis from a multicenter registry

Background: Upgrading to biventricular pacing (BVP) is currently the standard treatment for pacing-induced cardiomyopathy (PICM) patients. Although emerging literature suggests that upgrading to conduction system pacing (CSP) (including His bundle pacing, HBP, and left bundle branch area pacing, LBBAP) could be an effective alternative to BVP in the treatment of PICM, comparative data between these two upgrading strategies are lacking. Objective: To compare the effectiveness and safety of upgrading between CSP and BVP in a cohort of patients with PICM. Methods: Prospective, multicenter, observational study enrolling 183 consecutive patients with PICM (54.1% with NYHA class >II, mean left ventricular ejection fraction, LVEF, 33.2±8.4%), who underwent upgrading to CSP (n=69, of which 52 LBBAP, 17 HBP) or BVP (n=114). Propensity matching for baseline characteristics yielded 57 matched pairs. The primary endpoint was a composite of all-cause death and heart failure hospitalization (HFH). Secondary endpoints included the incidence of procedure-related complications, and change in LVEF and in NYHA class from baseline to 12-month follow-up. Results: During a median follow-up of 22.8 months, the primary endpoint occurred in 6 CSP patients (10.5%), and in 17 BVP patients (29.8%) (p=0.010). Procedure-related complications occurred in 2 CSP patients (3.5%), and in 8 BVP patients (14.0%) (p=0.047). Upgrading to CSP was associated with a significantly greater improvement in LVEF (+15.3±7.3 vs. +11.1±13.5%; p=0.039) and NYHA class (-1.3±0.7 vs. -0.8±0.8; p<0.001) at 12-month compared to BVP. Conclusions: In patients with PICM, upgrading to CSP could reduce the risk of all-cause death or HFH, as well as the incidence of procedure-related complications, compared to BVP.