In silico experiments explain the non-consistent benefit of conduction system pacing over cardiac resynchronization therapy. The need to personalize therapy

Abstract

Conduction system pacing (CSP) has emerged as an alternative treatment for patients with indication for cardiac resynchronization therapy (CRT). As opposed to biventricular CRT (BIV-CRT), which is based on left epicardial stimulation, CSP aims to restore the conduction through the His-Purkinje system pacing distally to level of block. Randomized evidence with His bundle pacing (HBP)(1–3) and left bundle branch pacing (LBBP)(4,5) is not extensive compared with the available BIV-CRT data. Non-inferiority of CSP as compared to BIV-CRT has been proven in a randomized trial (LEVEL-AT)(4); furthermore, the LBBP-RESYNC trial(5) has shown greater left ventricular (LV) ejection fraction improvement with LBBP versus BiV-CRT in non-ischemic patients with left bundle branch block (LBBB).