Conduction system versus biventricular pacing in heart failure with non‐left bundle branch block

Abstract

AbstractIntroductionThe benefits of cardiac resynchronization therapy (CRT) with biventricular pacing (BiV) is significantly lower when applied to heart failure (HF) patients with non‐left bundle branch block (LBBB) conduction delay. We investigated clinical outcomes of conduction system pacing (CSP) for CRT in non‐LBBB HF.MethodsConsecutive HF patients with non‐LBBB conduction delay undergoing CSP were propensity matched for age, sex, HF‐etiology, and atrial fibrillation (AF) in a 1:1 ratio to BiV from a prospective registry of CRT recipients. Echocardiographic response was defined as an increase in left ventricular ejection fraction (LVEF) by ≥10%. The primary outcome was the composite of HF‐hospitalizations or all‐cause mortality.ResultsA total of 96 patients were recruited (mean age 70 ± 11years, 22% female, 68% ischemic HF and 49% AF). Significant reductions in QRS duration and LV dimensions were seen only after CSP, while LVEF improved significantly in both groups (p < 0.05). Echocardiographic response occurred more frequently in CSP than BiV (51% vs. 21%, p < 0.01), with CSP independently associated with four‐fold increased odds (adjusted odds ratio 4.08, 95% confidence interval [CI] 1.34–12.41). The primary outcome occurred more frequently in BiV than CSP (69% vs. 27%, p < 0.001), with CSP independently associated with 58% risk reduction (adjusted hazard ratio [AHR] 0.42, 95% CI 0.21–0.84, p = 0.01), driven by reduced all‐cause mortality (AHR 0.22, 95% CI 0.07–0.68, p < 0.01), and a trend toward reduced HF‐hospitalization (AHR 0.51, 95% CI 0.21–1.21, p = 0.12).ConclusionsCSP provided greater electrical synchrony, reverse remodeling, improved cardiac function and survival compared to BiV in non‐LBBB, and may be the preferred CRT strategy for non‐LBBB HF.