Value of tissue Doppler echocardiography in predicting response to cardiac resynchronization therapy in patients with heart failure.

Several studies have demonstrated a relation between left ventricular (LV) dyssynchrony and response to cardiac resynchronization therapy (CRT). Many methods of determining LV dyssynchrony have been proposed, including a value of 65 ms as assessed by tissue Doppler imaging. The aim of the present validation study was to prospectively test the predictive accuracy of the 65-ms cutoff for LV dyssynchrony in a large cohort of patients with heart failure undergoing CRT. The study included 361 patients who had undergone CRT. The clinical and echocardiographic parameters were assessed at baseline and at 6 months of follow-up. The clinical response was defined as an improvement of > or = 1 New York Heart Association class, and the echocardiographic response was defined as a reduction in LV end-systolic volume of > or = 15%. At 6 months of follow-up, 259 patients (72%) had a clinical response and 187 patients (52%) had an echocardiographic response. The patients with a response had more LV dyssynchrony than did those without a response (91 + or - 49 ms vs 50 + or - 44 ms for the clinical response and 101 + or - 46 ms vs 55 + or - 45 ms for the echocardiographic response). On multivariate analysis, LV dyssynchrony remained predictive of the response, independent of other characteristics. In conclusion, LV dyssynchrony of > or = 65 ms was an independent predictor of both the clinical and the echocardiographic response in patients with heart failure who underwent CRT in this validation study. Copyright 2010 Elsevier Inc. All rights reserved.