Abstract 14755: Progressive Ventricular Dilatation Despite Cardiac Resynchronization Therapy (CRT): Baseline Predictors and Associated Clinical Outcomes
Introduction While echocardiographic evidence of reverse remodeling has been associated with improved outcomes in CRT, causes of and outcomes associated with progressive remodeling after CRT remain unclear.
Methods We conducted an analysis of 220 patients undergoing CRT with defibrillator for standard indications (LVEF<35%, NYHA III-IV, QRSd>120ms) to assess for predictors of, and clinical outcomes associated with, progressive remodeling. Progressive remodeling was defined a priori using an upper quartile cutoff of change in left ventricular end systolic diameter (LVESD). Endpoints included time until device treated ventricular arrhythmia (VA), time until electrical storm (ES), and first heart failure hospitalization (HFH) after CRT implantation. ES was defined as ≥3 device treated arrhythmias within 24 hours. Appropriateness of therapy was determined based on electrophysiologist review of stored device electrograms. Logistic regression analysis was performed to assess for predictors of progressive ventricular dilatation.
Results Subjects with progressive ventricular dilatation after CRT (n=40) (≥2mm increase in LVESD) were more likely to be NYHA III symptom class and have a history of sustained VA but were otherwise similar with regards to medical comorbidities, bundle branch morphology, medication use, lead position, LVESD and LVEF at baseline. Those with progressive dilatation were at increased risk for device treated VA (63% vs. 29%, p = 0.022), electrical storm (18% vs. 10%, p = 0.036) and 3-year HFH (56% vs. 39%, p=0.051). Logistic regression analysis identified NYHA III status, absence of beta-blocker use, and a history of previous VA as the only significant univariate predictors of progressive dilatation. Multivariate regression considering all univariate predictors with p<0.20 demonstrated beta-blocker use as the only independent significant predictor of LV dilatation and its use was associated with a reduction in the risk of dilatation (HR0.07, CI 0.01-0.69, p=0.023).
Conclusions Patients with progressive ventricular dilatation despite CRT represent a high risk group of non-responders at increased risk for worsened clinical outcomes. Beta-blocker use is associated with a reduced risk of progressive dilatation.
- © 2012 by American Heart Association, Inc.