Mp-453086-9 cardiac resynchronization therapy in heart failure with reduced ejection fraction: conduction system pacing versus biventricular pacing: a systematic review and meta-analysis

Conduction system pacing (CSP) is considered a more physiological form of pacing in patients requiring cardiac resynchronization therapy (CRT). Recently there are studies showing the benefit of CSP over biventricular pacing (BVP) among patients with heart failure with reduced ejection fraction (HFrEF). However, published data were based on small and mostly single-centered studies. To compare ECG, echocardiographic characteristics, and clinical improvement among patients with HFrEF undergoing CRT with CSP versus BVP. This study protocol is registered in the PROSPERO (CRD42022375155), and the review is conducted per PRISMA protocol. Four major databases were searched from inception till October 20, 2022, for relevant publications comparing conduction system pacing with biventricular pacing for cardiac resynchronization therapy indications in the HFrEF population. All relevant data were extracted in an excel spreadsheet. Data analysis was performed using RevMan 5.4 software. Dichotomous data variables were pooled using an odds ratio (OR) with a 95% confidence interval (CI). Continuous variable pooled using mean difference (MD). A total of 10,072 references were found in the database search. 35 studies were assessed for full days eligibility;18 studies (6 RCTs, 12 observational studies) with a total of 1375 patients were included in the review. Following left bundle branch area pacing (LBBAP), the average paced QRS duration was 28 ms narrower in comparison to BVP (MD -27.69, CI -36.59 to -18.80, n = 515), and a similar result was obtained in His bundle pacing (HBP) vs BVP (MD -31.76, CI -48.74 to -14.77; n= 413). LVEF significantly improved in CSP in comparison to BVP [LBBAP (MD 6.03, CI 4.16-7.91; n= 564); HBP (MD 3.79, CI 0.46-7.11; n= 260); His-Purkinje system pacing (HPSP) (MD 6.60, CI 4.42-8.78; n=477) (FIGURE). There were higher odds of being responders (OR 3.82, CI 1.88-7.75; n = 265)/super responders (OR 2.08, CI 1.53-2.82; n= 811) (per ECHO findings) in the CSP group, and overall mortality (OR 0.61, CI 0.40-0.93; n= 908) and hospitalization for heart failure (HHF) (OR 0.37, CI 0.25-0.55; n= 993) was lower in CSP group. Our analysis showed that CSP was superior to BVP with regard to ECG and echocardiographic parameters, as well as clinical outcomes in terms of mortality and HHF.