Left Bundle Branch Area Pacing Prevents New Onset Atrial Fibrillation and Improves Echocardiographic Parameters Compared with Right Ventricular Pacing in Patients with Bradyarrhythmias

Background/Objectives: Pacing treatment of bradyarrhythmias is both to reduce symptoms and to prevent syncope and sudden cardiac death. The aim of our study was to analyze left bundle branch area pacing (LBBAP) in the prevention of new-onset AF and the improvement of echocardiographic parameters in patients with mildly reduced left ventricular ejection fraction (LVEF) compared to patients with bradyarrhythmias but preserved LVEF who underwent mid-septal right ventricular pacing. Methods: This research was structured as a retrospective observational cohort study that included 186 patients with LBBAP and 186 patients with RVP, enrolled for 3 years until March 2024 with a follow-up time of 1 year. The primary endpoint of our study was new-onset atrial fibrillation after pacemaker implantation. The secondary endpoint was the improvement of echocardiographic parameters. Results: We observed in the LBBAP group a mean QRS complex duration of 108.7±8.83 ms (after pacemaker implantation), compared to a much longer duration in the RVP group (143.8±9.851 ms, p=0.0001). At 1 year follow-up, 22 (11.82%) patients in the RVP group were diagnosed with new-onset atrial fibrillation, compared to 6 (3.22%) patients out of 186 included in the LBBAP group (p=0.0017). Regarding LVEF, at follow-up, RVP patients had a decrease in LVEF compared to those in the LBBAP group who had an improved LVEF (54.54±3.77%, p=0.0001). Conclusions: LBBAP both prevents the onset of atrial fibrillation and improves echocardiographic parameters, especially left ventricular ejection fraction, thus contributing to significantly reducing the risk of developing/worsening advanced heart failure through pacing-induced cardiomyopathy.