In patients with HFrEF and LBBB, conduction system pacing was inferior to biventricular pacing for composite outcomes (OR 2.36; P = .002) at 12 months.
Does conduction system pacing improve a composite of clinical outcomes and LVEF compared to biventricular pacing in patients with HFrEF and LBBB?
In patients with HFrEF and LBBB, conduction system pacing was inferior to biventricular pacing for a composite of clinical events and LVEF improvement at 12 months, challenging its routine use as a first-line resynchronization strategy.
Absolute Event Rate: 0% vs 0%
Importance Conduction system pacing (CSP) is a promising and potentially cost-effective alternative to biventricular pacing (BiVP) in patients with heart failure with reduced ejection fraction (HFrEF) and left bundle-branch block (LBBB), but its impact on heart failure (HF) outcomes remains uncertain. Objective To compare CSP vs BiVP on an HF-related outcome in patients with HFrEF and LBBB. Design, Setting, and Participants PhysioSync-HF (Conduction System Pacing Versus Biventricular Resynchronization in Patients With Chronic Heart Failure) was an investigator-initiated, multicenter, noninferiority randomized clinical trial enrolling participants from November 2022 to December 2023 with 12 months of follow-up at 14 hospitals across all regions of Brazil. Adults with symptomatic HFrEF (New York Heart Association NYHA] classes II through III), left ventricular ejection fraction (LVEF) of 35% or less, and LBBB (QRS duration ≥130 milliseconds) were eligible for inclusion. Data were analyzed from May to August 2025. Intervention Patients were randomized 1: 1 to either CSP (preferentially left bundle-branch area pacing) or BiVP. Main Outcomes and Measures The primary outcome was a hierarchical composite of death, HF hospitalizations, urgent HF visits, and change in LVEF at 12 months. The prespecified noninferiority margin for the odds ratio (OR) was 1. 2. Results A total of 173 patients (median IQR age, 62 years 56-68; 86 female patients 49. 7%; 115 (66. 5%) with dilated cardiomyopathy; median IQR LVEF, 26% 22%-31%; median IQR QRS, 180 milliseconds 170-200) were included. At 12 months, CSP failed to meet noninferiority and was inferior to BiVP for the primary end point (OR, 2. 36; 95% CI, 1. 37-4. 06; P =. 99 for noninferiority; P =. 002 for between-group difference). The time-to-event composite of death, HF hospitalizations, or urgent HF visits was higher in CSP (hazard ratio, 2. 35; 95% CI, 0. 99-5. 61). Mean (SD) LVEF increased to 35% (12%) with CSP and 39% (12%) with BiVP (mean difference, 3. 8%; 95% CI, 0. 3%-7. 3%). Relative to baseline, both groups had comparable improvements in QRS duration, Kansas City Cardiomyopathy Questionnaire Overall Summary Score, NYHA class, and natriuretic peptide levels. Total direct medical cost related to the procedure and heart failure care was the equivalent of 7090 (95% CI, 5779-8648) lower in patients randomized to CSP at 12 months. Conclusions and Relevance In patients with HFrEF and LBBB, CSP was inferior to BiVP for a composite of death, HF hospitalizations, urgent HF visits, and change in LVEF at 12 months. These findings do not support the routine use of CSP as the first-line resynchronization strategy in this population. Trial Registration ClinicalTrials. gov Identifier: NCT05572736
Recent JAMA Cardiology publication with discussion in pacing/EP communities; relevant to CRT non-responders; increasing adoption of His/LBB pacing makes this timely.
Zimerman et al. (Wed,) reported a other. In patients with HFrEF and LBBB, conduction system pacing was inferior to biventricular pacing for composite outcomes (OR 2.36; P = .002) at 12 months.