Abstract 15106: Echocardiography versus Cardiac Magnetic Resonance-Quantification of Right Ventricular Function to Stratify the Risk of Appropriate Defibrillator Therapy

Abstract

Background: Right ventricular dysfunction is recently referred as an independent predictor of sudden cardiac death. The purpose of this study was to evaluate the efficiency of risk stratification methods for appropriate implantable cardiac defibrillator (ICD) therapy using two different modalities to quantify the right ventricular function. Methods: Consecutive patients undergoing ICD implantations who completed both preprocedural echocardiography and cardiac magnetic resonance (CMR) were retrospectively enrolled. Any channelopathy or arrhythmogenic right ventricular disease were excluded. The right ventricular fractional area change (RVFAC) and estimated pulmonary artery pressure (EPAP) were calculated from echocardiography. The contraction-pressure index (CPI) was defined as the quotient of the RVFAC divided by EPAP. The right ventricular ejection fraction (RVEF) was automatically provided by CMR. Both were evaluated to predict the initial appropriate ICD therapy. Results: In total, 111 patients (59.5±14.9 years, 79 males) including 20 with ischemic cardiomyopathy were retrospectively enrolled. Fifty-six patients received an ICD as secondary prophylaxis. The mean RVFAC, CPI, and RVEF were 36.7±8.9%, 1.4±0.7%, and 39.9±13.8%, respectively. Regarding appropriate ICD therapy events, the best cut-off value of the RVFAC was 34.8 (specificity 0.63, sensitivity 0.65, ROC-AUC 0.64), CPI 1.59 (specificity 0.42, sensitivity 0.94, ROC-AUC 0.61) and RVEF 43.0 (specificity 0.48, sensitivity 0.87, ROC-AUC 0.64). The hazard ratio of a low RVFAC was 3.13 (95%CI: 1.32-7.44, P<0.01, concordance=0.62), that of low CPI was 9.60 (95%CI: 1.27-72.4, P=0.03, c=0.65), and that of reduced RVEF was 5.55 (95%CI: 1.64-18.7, P<0.01, c=0.67). Conclusion: CPI and RVEF were similarly associated with an increased appropriate ICD therapy. The CPI seemed to provide an equivalent stratification for the risk of appropriate ICD therapy as compared to a CMR indicator.