Predicting factors of echocardiographic super‐response to cardiac resynchronization therapy

Abstract Purpose To investigate the clinical and echocardiographic predictors of echocardiographic super‐response to cardiac resynchronization therapy (CRT) in heart failure patients. Methods We retrospectively collected data from 97 patients, who underwent CRT and were followed up (median time = 20.33 months). All had left ventricular ejection fraction (LVEF) ≤35%, New‐York‐Heart‐Association class 3 or 4, and Q wave, R wave and S wave (QRS) duration >120 ms. Time‐to‐peak systolic velocity was measured for individual LV segments by tissue Doppler imaging prior to CRT. Two‐dimensional echocardiography was carried out before and at follow‐up, and ≥12.5% increase in LVEF was defined as super‐response. Results From the 97 patients, 23 (23.7%) were super‐responders. Super‐responders were more frequently female (52.2% vs. 24.3%, respectively; p value = 0.012). Among super‐responders, the mean of LV end‐diastolic and end‐systolic volumes were significantly lower. According to dyssynchrony indices, time delay between anteroseptal and posterior wall and SD of all LV segments timing showed significantly higher values in super‐responders. By multivariate analysis, LV end‐systolic volume and anteroseptal‐to‐posterior wall delay remained independently associated with echocardiographic super‐response to CRT. Conclusion About one‐fourth of our patients with CRT were super‐responder in that they had ≥12.5% increase in LVEF by echocardiography. Among all the clinical and echocardiographic measures, only lower LV end‐systolic volume and higher anteroseptal‐to‐posterior wall delay predicted super‐response.