Abstract 3285: Echocardiographic Predictors of Left Ventricular Reverse Remodeling after Cardiac Resynchronization Therapy: a prospective Comparative Study
Introduction: To date no single echo criteria can predict successful cardiac resynchronization therapy (CRT) over current guidelines. Real-time three-dimensional echocardiography (RT3DE) provides 3D dynamic information of LV contractility. Hypothesis: We tested the hypothesis that significant dyssynchrony can be a sum of longitudinal, radial and circumferential dyssynchrony. We prospectively investigated RT3DE against conventional echocardiographic parameters of inter- and intra-ventricular mechanical dyssynchrony for prediction of CRT outcome.
Methods: Sixty-nine patients (age, 62 ± 12 years; 72% male, 42% ischemic etiology) CRT implantation according to the AHA/ACC/ESC guidelines. Using the iE33 Philips, all patients underwent standard 2D echo-Doppler study, color-tissue Doppler (c-TDI, minimum frame rate of 90 Hz) and RT3DE before and one-year after CRT. Variables were recorded namely: septal-to-posterior wall motion delay (SPWMD) on M-mode, systolic dyssynchrony index (SDI) measured by c-TDI (TDI-SDI) was defined as standard deviation of time to peak systolic velocity of the 12-LV segments (6 basal and 6 mid) and 3D-SDI is the standard deviation of 16-LV segments. Inter-ventricular dyssynchrony was defined as the difference between onset of aortic and pulmonary flow on PW-Doppler. All variables were expressed as % of cardiac cycle. Responders were defined as >1 class improvement of NYHA plus >25% increase in the 6-minute walking distance plus >15% reduction of LV end-systolic volume. ROC curves were generated for each echocardiographic variable for prediction of CRT responders and for determination of cut-off values. Linear regression analysis was performed to investigate the relation between the change in LV-ESV after CRT and different echocardiographic variables.
Results: At one-year, 46 patients (67%) patients were responders. A 16% 3D-SDI had the highest sensitivity and specificity with the largest area under the curve 0.83 for the prediction of echocardiographic responders at one-year follow-up.
Conclusions: 3D echocardiography provides a superior utility over conventional echocardiography and TDI parameters for selection of appropriate candidates for CRT.