Abstract 2139: Tissue Synchronization Imaging Accurately Measures Left Ventricular Dyssynchrony and Predicts Response to Cardiac Resynchronization Therapy
Aim Tissue synchronization imaging (TSI) is a new technique to assess left ventricular (LV) dyssynchrony automatically; in the current study the value of TSI to assess LV dyssynchrony automatically was compared directly to manual assessment of LV dyssynchrony from color-coded tissue Doppler imaging (TDI). In addition, the value of TSI to predict response to cardiac resynchronization therapy (CRT) was evaluated.
Methods Sixty consecutive patients with end-stage heart failure, depressed LVEF (mean 23±8%), New York Heart Association (NYHA) class III or IV, and QRS duration >120 ms were evaluated echocardiographically at baseline and after 6 months of CRT. LV dyssynchrony was measured manually using velocity tracings from the color-coded tissue Doppler images and automatically using TSI. LV volumes and LVEF were assessed from 2D echocardiography; reverse LV remodeling was defined as ≥15% reduction in LV end-systolic volume. Clinical parameters including NYHA functional class, quality of life and 6-min walking distance were assessed at baseline and after 6 months of CRT.
Results There was a strong correlation between LV dyssynchrony measured manually from the color-coded TDI and automatically derived by TSI (r=0.95, p<0.0001). Bland-Altman analysis showed excellent limits of agreement between manual and TSI assessment of LV dyssynchrony. Thirty-four patients showed reverse LV remodeling after 6 months of CRT and were classified as responders. Baseline characteristics were comparable between responders and non-responders, except for more extensive LV dyssynchrony at baseline in the responders: 78±26 ms versus 29±29 ms (p<0.0001) as assessed manually from color-coded TDI, and 79±29 ms versus 28±27 ms (p<0.0001) as assessed automatically by TSI. Using a cutoff value of 65 ms to define extensive LV dyssynchrony, TSI had sensitivity of 81% with a specificity of 89% to predict reverse LV remodeling.
Conclusion TSI allows automatic and reliable assessment of LV dyssynchrony and predicts reverse LV remodeling after CRT.