A strain-based LBBB classification predicts the degree of reverse remodeling and outcome in patients with cardiac resynchronization therapy

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main source(s): Research Foundation Flanders (FWO). Introduction Septal strain patterns measured by echocardiography reflect the gradual process left bundle branch block (LBBB)-induced ventricular (LV) remodeling. We investigated whether these stages also predict progressive volumetric response and outcome in cardiac resynchronization therapy (CRT) patients. Methods This prospective study enrolled consecutive CRT patients from 5 European centers who underwent echocardiographic examination with speckle-tracking analysis before implantation. Dyssynchrony was assessed using septal curves, which were classified into (stage LBBB-0 to LBBB-4). The magnitude reverse remodeling determined at 1 year. pre-defined death any cause or heart transplantation. Results involved 267 (age 66±11 years; 69% men; 90% LBBB) a mean LV ejection fraction (EF) 30±7%. Across stages, resulted response, ranging almost no (ΔLV end-systolic volume −9 ±21ml; ΔLVEF +4±8%) super-response LBBB-4 −85 ±54ml; +20±9%) (p<0.001 for both). Median follow-up 49 months. had worst (log rank p = 0.002, Figure), subsequent LBBB gradually showing more favorable 0.045, Figure). There stepwise decrease adverse events according staged classification. 4 predicted long-term survival without transplantation respective hazard ratios 0.61 (95% CI 0.25–1.50), 0.26 0.10–0.68), 0.29 0.11–0.77) 0.13 0.04–0.51) compared LBBB-0. After multivariable adjustment baseline LVEF, ischemic disease presence an implantable cardioverter defibrillator, staging remained significantly associated decreased risk (hazard ratio 0.69 0.51–0.92) per 1-stage increase). Conclusions are extent proposed classification provides pathophysiological insights LBBB-induced dysfunction may be helpful identify benefit most