Abstract
BACKGROUND: Right ventricular pacing (RVP) has been associated with an increased risk of atrial fibrillation (AF). OBJECTIVE: We aim to compare the incidence of new-onset AF between left bundle branch pacing (LBBP) and RVP. METHODS: We conducted a prospective, observational, 2-center study recruiting patients with pacemaker implantation who were at high risk of developing AF (ie, patients older than 70 years). The primary end point was time to the first occurrence of device-detected AF with clinical significance (ie, AF lasting >6 minutes), whereas the secondary end point was time to the first episode of AF that could require oral anticoagulation (ie, AF lasting >24 hours). Multivariate Cox regression models were used to evaluate the effect of LBBP on AF occurrence. RESULTS: The final evaluation included 412 patients (212 (51.4%) in the LBBP group and 200 (48.5%) in the RVP group). LBBP showed a lower incidence of AF lasting >6 minutes than did RVP (27.4% vs 42%; P = .003). Multivariate analysis showed that LBBP presented a lower hazard ratio (HR) for AF lasting >6 minutes than did RVP (HR 0.575; 95% confidence interval [CI] 0.411-0.804; log-rank, P = .001). Among patients with ventricular pacing ≥20%, LBBP was associated with a lower risk of AF compared with RVP (HR 0.510; 95% CI 0.341-0.764; P = .001). LBBP demonstrated a reduced risk of new-onset AF lasting >24 hours compared with RVP (9.4% vs 25%; P < .001). Multivariate analysis further confirmed that LBBP had a lower HR than did RVP (HR 0.354; 95% CI 0.210-0.595; log-rank, P < .001). CONCLUSION: LBBP reduced the risk of new-onset device-detected AF lasting >6 minutes and decreased the likelihood of new-onset AF episodes lasting >24 hours, compared with RVP in a high-risk population for AF development.