Comparison of his bundle pacing versus biventricular pacing in heart failure: a systematic review and meta-analysis

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Despite optimal medical treatment, the 5-years mortality and HF readmission rate was 75.3% and 48.5%, respectively. The current guidelines recommended cardiac resynchronization therapy (CRT) by implanting biventricular pacing (BVP) for specific group of patients with HF with reduced ejection fraction (HFrEF) in order to reduce the mortality and the risk of HF events by 34%. However, 20% to 40% patients might not respond or even get clinical deterioration after receiving such device. To overcome the non-responders, His bundle pacing (HBP) emerges recently as one of the therapeutic options. His bundle pacing implantation potentially results in the narrower QRS duration as well as more improvement in left ventricle (LV) function compared with BVP in patients with LBBB. On top of that, HBP might become a more cost-effective solution, compared to CRT, particularly for the majority of developing countries in Asia. Purpose We aim to elaborate the clinical efficacy of HBP in specific patients with HF, compared to BVP. This HBP was implanted either as a primary therapeutic strategy for CRT candidates or as a rescue strategy for BVP non-responders. Methods This study is registered. A structured search was conducted in Pubmed, Embase, and Clinicaltrial.gov. Inclusion criteria were: Age >18 years old, NYHA II-IV, QRS duration ≥120 milliseconds, and left (LBBB) or right bundle branch block (RBBB) morphology. The primary endpoints were change in QRS duration, improvement in LVEF, improvement in NYHA class, and cardiovascular (CV) event. Results A total of 8 final articles involving 361 HF patients were included for analysis, with a male preponderance. The QRS duration was significantly narrower in HBP (MD: -23.44; 95%CI -34.92 to -11.97; P<0.001) compared to BVP. There was no statistically significant LVEF improvement between HBP group and BVP group in HF patients who were CRT candidates (MD: 4.63; 95%CI -4.47 to 13.74; P=0.32). The improvement in NYHA class varied between studies. One study reported comparable improvement between HBP and BVP, while another study reported better improvement in HBP compared to BVP. In terms of CV outcome, there was no significant difference in CV hospitalization and mortality rate. Heart failure hospitalization occurred both in HBP and BVP group, but the difference was not significant between groups. Improvement in QRS duration, LVEF, and NYHA class occurred in both LBBB and RBBB. Conclusion(s) HBP provides better electrical resynchronization compared to BVP. Additionally, some degree of reverse LV remodelling was also observed in HBP group of patients with either LBBB and RBBB patterns. However, the benefits of HBP in reducing HF hospitalization and CV mortality remain indeterminate. Further RCTs with large samples are still required to evaluate the superiority of HBP, compared to BVP for CRT, in reducing mortality and HF hospitalization.