Are the Extent,Location, and Score of Segmental Wall Motion Abnormalities Related to Cardiac Resynchronization Therapy Response?

Background: We hypothesized that segmental wall motion abnormalities (WMAs) are related to cardiac resynchronization therapy (CRT) response. Methods: We studied 108 patients who received CRT, 69 with ischemic and 39 with nonischemic heart disease. A wall motion score index (WMSI) was analyzed using a 17‐segment model and calculated by the total score/number of segments analyzed. A decrease of left ventricular end systolic volume ≥15% after CRT was defined as a positive response to CRT. Results: Of 108 patients, 1,054/1,836 segments (57%) had WMAs. The mean WMSI was 2.06 in patients with ischemic heart disease and 1.04 in patients with nonischemic heart disease (P < 0.0001). The area under the receiver operating characteristic curve for a WMSI predicting a positive response to CRT was 0.70 (P = 0.0001). The cutoff point was a WMSI ≤2 for prediction of a positive response to CRT. After adjustment for age, gender, and clinical features, the WMSI persistently related to CRT responders (P = 0.01). During 15‐month follow‐up, the percentage of CRT nonresponders in patients with a WMSI >2 was significantly higher (82%) compared to patients with a WMSI ≤2 (47%, P = 0.005) and nonischemic heart disease (36%, P < 0.001). In 59 patients with left ventricular mechanical dyssynchrony, the percentage of negative responders to CRT in patients with a WMSI >2, ≤2, and nonischemic heart disease were 53% (8 of 15), 16% (3 of 19) and 0% (0 of 25), respectively (P < 0.001). Conclusions: A large extent of WMAs and a WMSI >2 predicted a poorer CRT response. (ECHOCARDIOGRAPHY, Volume 26, November 2009)