We hypothesized that the extent, location and score of segmental wall motion abnormality (WMA) are related to response of cardiac resynchronization therapy (CRT).
We studied 108 patients who received CRT (male 78, age 69.9 ± 9.7 years). Patients with atrial fibrillation were excluded. There were 69 patients with ischemic heart disease. 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.
There were 1,054/1,836 segments (57%) with WMA before CRT. The segments with WMA in CRT non-responders were significantly greater than CRT responders (69% vs 43%, p < 0.001). Segments with WMA were more frequently attributed to left anterior descending coronary artery (LAD) in CRT non-responders (89%) compared to CRT responders (63%, p < 0.001). Mean WMSI was 1.80 ± 0.64. WMSI in patients with ischemic heart disease was significantly greater than non-ischemic heart disease (2.06 ± 0.59 vs 1.04 ± 0.07, p < 0.0001). The area under ROC curve (AUC) for WMSI predicting positive response to CRT was 0.70 (p = 0.0001, Fig). The cutoff point was WMSI≤; 2 for prediction of positive response to CRT. After adjustment for age, gender and clinical variables, WMSI continued to be related to CRT responders (p = 0.01) and associated with high Nagelkerke R2 (0.66, p < 0.0001). During follow-up of 15 ± 10.9 months, the percentage of CRT non-responders in patients with WMSI > 2 was significantly higher (82%) compared to patients with WMSI≤; 2 (47%, p = 0.005) and non-ischemic heart disease (36%, p < 0.001). Of 59 patients with left ventricular dyssynchrony, 11/59 (19%) patients had negative response to CRT.
The large extent of WMA, WMA in the segments attributed to LAD and WMSI > 2 predicted a poorer CRT response even in patients with echocardiographic demonstrated LVMD.
Wall motion score index > 2 predicted a poorer CRT response.
Xuedong Shen, No Financial Disclosure Information; No Product/Research Disclosure Information