New-onset atrial high-rate episodes in left bundle branch area pacing versus right ventricular pacing for patients with atrioventricular block

Background: Left bundle branch area pacing (LBBAP) demonstrated beneficial effects on clinical outcomes. Comparative data on the risk of atrial high-rate episodes (AHREs) between LBBAP and right ventricular pacing (RVP) are lacking. Aims: This study aimed to investigate whether LBBAP can reduce the risk of new-onset AHREs compared with RVP in patients with atrioventricular block (AVB). Methods: We enrolled 175 consecutive AVB patients with no history of atrial fibrillation undergoing dual-chamber pacemaker implantation (LBBAP or RVP). Propensity score matching for baseline characteristics yielded 43 matched pairs. The primary outcome was new-onset AHREs detected on a scheduled device follow-up. Changes in echocardiographic measurements were also compared between the groups. Results: New-onset AHREs occurred in 42 (24.0%) of all enrolled patients (follow-up 14.1 [7.5] months) and the incidence of new-onset AHREs in the LBBAP group was lower than in the RVP group (19.8% vs. 34.7%; P = 0.04). After propensity score matching, LBBAP still resulted in a lower incidence of new-onset AHREs (11.6% vs. 32.6%; P = 0.02), and a lower hazard ratio for new-onset AHREs compared with RVP (HR, 0.274; 95% CI, 0.113-0.692). At 1 year, LBBAP achieved preserved left ventricular ejection fraction (LVEF) (63.0 [3.2]% to 63.1 [3.1]%; P = 0.56), while RVP resulted in reduced LVEF (63.4 [4.9]% to 60.5 [7.3]%; P = 0.01]). Changes in LVEF were significantly different between the 2 groups (by 2.6% [0.2 to 5.0]%; P = 0.03). Conclusion: LBBAP demonstrated a reduced risk of new-onset AHREs compared with RVP in patients with AVB.