Left bundle branch pacing is a superior pacing strategy compared to left ventricular septal pacing: insights from the pooled clinical evidence.

BACKGROUND: Left bundle branch pacing (LBBP) is proposed as a superior physiological pacing method to left ventricular septal pacing (LVSP). However, its comparative benefits on hard clinical outcomes remain inadequately defined. METHODS: We systematically searched four databases for studies comparing LBBP with LVSP. The primary outcomes were all-cause death or heart failure hospitalization (HFH), all-cause death, HFH, or malignant ventricular arrhythmias. Subgroup analyses were performed to identify effect modifiers for the paced QRS duration and left ventricular ejection fraction (LVEF) at follow-up. RESULTS: Fourteen studies with 1,592 patients were included. LBBP was associated with reduced risks of all-cause death/HFH (risk ratio [RR] = 0.25), all-cause death (RR = 0.30), HFH (RR = 0.26), and malignant ventricular arrhythmias (RR = 0.36). LBBP also resulted in a QRS narrowing and greater LVEF improvement. Subgroup analyses demonstrated significantly greater improvement in paced QRS duration and LVEF in the patient subgroups under 70 years of age and those with cardiac resynchronization therapy (CRT) indications. CONCLUSIONS: LBBP may be superior to LVSP, reducing mortality, heart failure, and arrhythmic events. Younger patients and those requiring CRT derive the greater benefit. These promising findings support LBBP as a preferred physiological pacing strategy, but large-scale randomized trials are needed to confirm these results. CLINICAL TRIAL REGISTRATION: https://www.crd.york.ac.uk/PROSPERO/view/CRD420251031432, identifier CRD420251031432.