Incidence of Atrial Fibrillation in Pacemaker Patients with Left Bundle Branch Area Pacing Versus Right Ventricular Pacing Leads.

BACKGROUND: Guidelines and early clinical data indicate left bundle branch area pacing (LBBAP) may help avoid pacing induced cardiomyopathy, but the impact of LBBAP on atrial fibrillation (AF) is less certain. OBJECTIVE: To compare new onset AF in patients with LBBAP leads with RVP leads. METHODS: RVP leads (N=5225) and LBBAP leads (N=4970) in the RV port of dual chamber pacemakers were identified in the LATITUDE remote monitoring database. Patients without prior AF were propensity score matched requiring an exact match on percent RV pacing group (<1%, 1-39%, 40-98%, ≥99%) based on a 90-day baseline period and a 0.01 caliper on age, sex, pacing mode, lower rate limit, percent RA pacing (continuous), and percent RV pacing (continuous within exact match groups). Time spent in atrial tachy response mode was used to identify AF burden. Landmark analysis was performed as time to first 24-hour AF episode. RESULTS: Propensity matching yielded 7886 patients (3943 LBBAP and 3943 RVP). No propensity match characteristics were significantly different between groups. The overall percentage of patients with 24-hour AF was significantly lower in the LBBAP group over 21 months of follow-up (13% LBBAP vs 15% RVP, P=0.037). When stratified into percent RV pacing ≥ or <40%, the RVP group had significantly more 24-hour AF observed when percent pacing was >40% (LBBAP<40%: 13%; RV<40%: 13%; LBBAP≥40%: 13%; RV≥40%: 16%; P=0.004). CONCLUSION: LBBAP was associated with a lower incidence of onset of new AF than RVP in pacemaker patients with a high pacing burden.