Left bundle branch pacing for cardiac resynchronization therapy: A systematic literature review and meta-analysis

Left bundle branch pacing (LBBP) recently has been suggested as an alternative modality to deliver cardiac resynchronization therapy (CRT). Data on LBBP for CRT are limited to small sample reports, and clinical benefits and risks have not been systematically assessed. We sought to systematically examine published studies of LBBP for CRT and quantify the feasibility and efficacy of the therapy.

Cochrane Library, PubMed, Web of Science, and Embase databases were searched from inception to September 30, 2020 to identify relevant studies evaluating LBBP in patients for CRT. Clinical outcomes of interest included implant success rate, QRS duration (QRSd), pacing threshold, left ventricular (LV) function at baseline and follow-up, heart failure-related hospitalization, and mortality. Data were extracted and summarized.

A total of six studies (two single-arm studies and four comparative studies) involving 174 patients were included. The results showed that the average age of patients was 64.9 years and all were implanted for CRT. The procedural success rate was only reported in two studies (97% and 81.1%, respectively). LBBP resulted in a narrow of mean QRSd from 172.7 ± 4.8 to 115.1 ± 7.6 ms. LV function, including LV ejection fraction and LV end-diastolic dimension improved at follow-up. During a mean follow-up of 8.1 months, 1.3% of patients experienced heart failure-related hospitalization and no patients died.

LBBP is a feasible strategy with significant efficacy and safety for CRT candidates.