Abstract 12635: A Novel Method to Predict Response to Cardiac Resynchronization Therapy by Tissue Mitral Annular Displacement (TMAD)
Background: Echocardiographic measurement of left ventricular (LV) dyssynchrony has a limited ability to predict response to cardiac resynchronizing therapy (CRT) in severe heart failure (HF) patients because of high variability of measurement. Tissue mitral annular displacement (TMAD), a novel method to measure the valvular annular displacement over time using 2D-speckle tracking technique, is a rapid and robust method for the assessment of LV longitudinal deformity. We investigated the ability of TMAD technique to predict response to CRT in patients with severe HF.
Methods and Results: We performed echocardiography study in 37 patients with dilated cardiomyopathy (DCM) before and at 6 month of CRT, using iE33 (Philips Medical Systems). TMAD measurement was performed on an apical 4-chamber image using off-line QLAB software (Philips Medical Systems). We measured the time between QRS on electrocardiogram to peak of displacement on septal- and lateral part of mitral annuls separately (Figure), and calculated the differences in time-to-peak as an index of LV dyssynchrony. TMAD measurements were successfully completed within 2 minutes in all patients. Decrease in LV end-systolic volume (LVESV) > 15% after CRT was observed in 24 patients (65%), and designated as responders to CRT. The responders had significantly longer time-to-peak on TMAD analysis than the non-responders (161.9±64.0 vs. 55.5±65.2 msec, p<0.001). Improvement in ejection fraction (EF) >15% was observed in 22 patients, and they also had longer time-to-peak than others (150.2±68.7 vs. 86.9±87.0 msec, p=0.02). Using 82 msec as a cutoff value, time-to-peak on TMAD detected CRT responders with sensitivity of 87.5% and specificity of 84.6% (AUC=0.87).
- © 2012 by American Heart Association, Inc.