His bundle pacing for cardiac resynchronization therapy: a systematic literature review and meta-analysis.

BACKGROUND: Permanent His bundle pacing has been to shown to be an alternative for the patients with CRT indications and more recently has been evaluated for feasibility as a first-line strategy. Data on His bundle pacing (HBP) for cardiac resynchronization therapy are largely limited to small single-center reports, and clinical benefits and risks have not been systematically examined. The purpose of this study was to systematically review published studies of HBP for cardiac resynchronization therapy and evaluate the feasibility and efficacy of the therapy.

METHODS: PubMed, Cochrane Library, Embase, CNKI, and WANFANG databases were searched up to December 2019 to identify relevant studies. Clinical outcomes of interest include implant success rate; Q wave, R wave, and S wave QRS duration; pacing thresholds; left ventricular ejection fraction (LVEF); left ventricular end-diastolic dimension (LVEDD); and New York Heart Association (NYHA) status, complications, and mortality. Extract and summarize the data. Using Revman5.3 software to perform the meta-analysis.

RESULTS: A total of 13 studies involving 503 patients were included. The average implant success rate was 79.8% (95% CI 72.4-87.2%). Permanent HBP resulted in a significant narrow of mean QRS duration from 165.5 ± 8.7 to 122.9 ± 12.0 ms (MD = 43.5, 95%Cl: 36.34 ~ 50.56, p < 0.001). A trend of increase was observed in capture thresholds at follow-up compared with that in the baseline threshold (MD = - 0.24, 95% Cl: - 0.38 ~ - 0.10, p = 0.001). Average NYHA functional class (MD = 1.2, 95% CI: 1.09 ~ 1.31, p < 0.001), LVEF (MD = - 12.60, 95% Cl: - 14.32 ~ - 10.87, p < 0.001), LVEDD (MD = 4.30, 95% Cl: 3.05 ~ 5.55, p < 0.001) significantly improved at > 3 months follow-up compared with that of the baseline (p < 0.001). Ten studies reported safety information and the most commonly reported complication was the increase in HB capture threshold.

CONCLUSIONS: HBP is feasible with a reasonable success rate in patients requiring CRT. HBP could achieve significant narrow of QRS duration and improve left ventricular function during follow-up. Randomized controlled trials are needed to further assess the efficacy of HBP compared with that of biventricular pacing (BVP) in achieving CRT. Graphical abstract Schematic representation of detecting ofloxacin (OFL) by differential pulse voltammetry approach based on the laser modified glassy carbon electrode (LGCE), which increased the active functional groups and surface area compared to GCE.