Conduction system pacing vs. biventricular pacing for cardiac resynchronization therapy in heart failure with reduced ejection fraction: An updated systematic review and meta-analysis

Conduction system pacing (CSP) is considered an effective and physiological form of pacing in patients requiring cardiac resynchronization therapy (CRT). To compare electrocardiographic (ECG), echocardiographic (ECHO) characteristics and clinical outcomes among patients with heart failure with reduced ejection fraction (HFrEF) undergoing CRT with CSP or biventricular pacing (BVP). This study protocol was registered in the PROSPERO registry (CRD42022375155) and the review was conducted per the PRISMA protocol. Four major databases were searched from inception till October 20, 2022, for relevant studies comparing CSP to BVP for CRT in patients with HFrEF. From a total of 10,072 references identified, 35 full-text were assessed and 18 studies (6 RCTs, 12 observational studies) were included in the review. Following left bundle branch area pacing (LBBAP), on average, paced QRS duration was 28 ms narrower in comparison to BVP (MD -27.69, CI -36.59 to -18.80), and a similar result was obtained with HBP vs. BVP as well. Left ventricular ejection fraction (LVEF) improvement was greater with CSP in comparison to BVP [LBBAP (MD 6.03, CI 4.16-7.91); HBP (MD 3.79, CI 0.46-7.11); HPSP (MD 6.60, CI 4.42-8.78). There were higher odds of being responders (OR 3.82, CI 1.88-7.75)/super responders (OR 2.08, CI 1.53-2.82) (per ECHO findings) in the CSP group, and overall mortality (OR 0.61, CI 0.40-0.93) and hospitalization for HF (HHF) (OR 0.37, CI 0.25-0.55) was lower in CSP group. Our analysis showed better ECG, ECHO, and clinical outcomes in terms of mortality and HHF with CSP compared to BVP.