Publication

Abstract :

Introduction Atrial fibrillation (AF) is a highly prevalent arrhythmia that is associated with a greater risk towards cerebrovascular accidents (CVA), heart failure (HF) and all-cause mortality. Atrioventricular node ablation (AVNA) with permanent pacemaker implantation is an established treatment approach for patients with AF demonstrating refractory and uncontrolled ventricular rates. Conduction system pacing (CSP) utilising His bundle pacing (HBP) or left bundle branch area pacing (LBBAP), has advanced as an alternative to conventional pacing (CP) (including right ventricular pacing (RVP) and biventricular pacing (BVP). This systematic review and meta-analysis aims to provide a comprehensive summary and evaluation of clinical outcomes in the literature for CSP in comparison to CP when facilitated with AVNA.

Methods This study protocol was registered in the PROSPERO registry (CRD42024510974) and the review was conducted as per the PRISMA guidelines. MEDLINE, EMBASE and Cochrane Library were searched for relevant studies from inception till January 11th, 2024. Results were synthesised using a random effects meta-analysis. Risk of bias (ROB) assessment was carried out with the RoB 2 and ROBINS-I tool.

Results From a total of 259 references identified, 122 full texts were assessed and 6 studies (2 randomised control trials, 2 prospective observational studies, and 2 retrospective observational studies) were included in the review. A total of 756 (HBP-312 and LBBAP-444) and 444 (BVP-369 and RVP-75) patients received CSP and CP implantation with AVNA , respectively. All devices were implanted successfully with a cumulative total of 4 patients in the CSP population demonstrating acute threshold hold increase following AVNA. There was no loss of capture on follow-up in either treatment groups. CSP resulted in a narrower QRS duration (QRSd) with a reduction of -43.4 ms (95% confidence interval [CI] -62.3 to -24.6; P<0.05; I2=94.9%) vs CP. For left ventricular ejection fraction (LVEF), a weighted mean increases of 3.77% (95% CI 0.61%-6.93%; P=0.04, I2=54.2%) was observed following CSP implantation in comparison to CP . The mean NYHA score was reduced by -0.59 (95% [CI] -0.93 to -0.26; P<0.05, I2=53.9%) after CSP implantation when compared to CP. There was a cumulative total of 45 and 65 events of heart failure associated hospitalisation in the CSP and CP groups (Risk diff: 0.06; 95% CI -0.03–0.14; P=0.05, I2 =65.8), respectively. A subgroup analysis of outcomes stratified by LBBAP and HBP also demonstrated statistically significant weighted mean improvement of QRSd and LVEF with both CSP modalities compared with BVP when facilitated with AVNA.

Conclusion To our knowledge, this is the first methodologically robust systematic review and meta-analysis evaluating the outcomes of CSP with AVNA. Overall, CSP demonstrated feasibility and application as an effective CRT alternative to facilitate AVNA along with a narrower QRSd ,improved LVEF and NYHA score as well as a trend of better clinical outcomes. While these preliminary findings are promising, further RCTs will be necessary to establish the long-term efficacy and safety of this approach.