Abstract 14930: Baseline Adverse Electrical Remodeling and the Risk for Ventricular Arrhythmia in Cardiac Resynchronization Therapy Recipients (MADIT CRT)
Introduction: Adverse electrical remodeling (AER), measured as the integral of the QRST segment (QRSTi) has been previously shown to be directly associated with the risk for ventricular arrhythmia (VA). Cardiac resynchronization therapy (CRT) is known to reduce the risk for VA through different mechanisms. We aimed to evaluate the association between baseline AER and the risk for VA in CRT recipients
Methods: The study population comprised 961CRT-D implanted patients from the MADIT CRT study. Signal averaging procedure was applied to compute representative beats from the 20-minute ECG ensuring that the selected beats were at stable heart rate. QRSTi was measured across the 3 orthogonal leads. The relationship between QRSTi and the risk for VA and VA/death was evaluated as a continuous and as a categorical variable - tertiles (T1≤0.527, T2 0.528-0.766, T3>0.766).
Results: In a multivariable model, AER was inversely associated with the risk of VA. Each unit increase in QRSTi was associated with 64% (p=0.007) and 54% (p=0.003) decrease in the risk of VA and VA/death, respectively. Patients with high QRSTi (T3) and medium QRSTi (T2) had 52% (p<0.001) and 32% (p=0.027) reduced risk for VA and 44% (p=0.002) and 26% (p=0.055) reduced risk for VA/death as compared with patients with low QRSTi (T1), respectively. Importantly, this association was sustained even in patients with non-LBBB configuration.
Conclusions: In CRT implanted patients with mild heart failure baseline AER was inversely associated with the risk for VA and VA/death. This finding suggests that the adverse process of electrical remodeling could be reversed with CRT, providing a mechanistic explanation for the reduction of VA risk with this treatment modality.
Author Disclosures: Y. Biton: None. Y. Shapovalov: None. X. Xia: None. J. Couderc: None. A. Moss: Research Grant; Significant; grant support from Boston Scientific. V. Kutyifa: Research Grant; Significant; grant support from Boston Scientific. S. Mcnitt: None. B. Polonsky: None. W. Zareba: Research Grant; Significant; grant support from Boston Scientific.
- © 2016 by American Heart Association, Inc.