Introduction
Heart failure is a global health problem, with over 64 million patients worldwide and over one million hospitalizations annually in the United States alone1, 2. Heart failure with reduced ejection fraction (HFrEF) can be associated withleft and right ventricle desynchrony, which is hemodynamically disadvantageous and related to increased mortality3. Cardiac resynchronization therapy (CRT) is an established effective treatment for selected patients with HFrEF and , abnormal ventricular conduction resulting in wide QRS complex4-8. Conventionally, CRT is achieved by right ventricular and left ventricular pacing via coronary sinus (biventricular pacing, BVP). However, the success rate is highly related to coronary sinus anatomy (small caliber target vessels, tortuosity, and coronary sinus valves), and up to 30% of patients do not adequately respond to BVP CRT5, 9, 10.
Conduction system pacing (CSP), including His bundle pacing (HBP) and left bundle branch area pacing (LBBP), was introduced in an attempt to mitigate these challenges by physiologically pacing the His-Purkinje system. His bundle pacing, however, requires a higher pacing threshold , and may not correct left bundle branch block (LBBB) below the level of His bundle11-14. LBBP was first introduced in 2017 in humans and has emerged as a feasible and safe alternative to BVP to achieve cardiac resynchronization with accumulating supporting data15-18. Hence, the objective of this study was to conduct a systematic review and meta-analysis of current studies to compare the efficacy of LBBP and BVP CRT in HFrEF patients.