Keeping pace with the competition: His bundle versus biventricular pacing in heart failure.

Abstract

His bundle pacing (HBP) has emerged as a novel method to achieve electrical resynchronization in bundle branch block and as an alternative means to deliver cardiac resynchronization therapy (CRT). There are now data on HBP in CRT-eligible patients from cohort studies and a single pilot randomized controlled trial (RCT). Early clinical data regarding HBP in heart failure have demonstrated echocardiographic and functional improvement similar to traditional biventricular pacing (BiV), mostly when utilized as a bailout to traditional BiV-CRT. A single pilot RCT, His-SYNC, showed a trend toward greater echocardiographic response in an on-treatment analysis, but was underpowered. No large RCTs have reported long-term clinical outcomes. In order to realize any benefit from HBP, output-dependent morphology changes must be demonstrated to ensure the conduction system capture is present. There may be a role for corrective HBP in patients with right bundle branch block and after atrioventricular node ablation, which is theoretically more desirable than traditional BiV. Importantly, however, HBP is likely not to benefit patients with nonspecific intraventricular conduction delay. HBP is emerging as an alternative strategy for CRT and may have a role in patients in whom traditional BiV is not achievable or ineffective.