Abstract 2816: Assessment Of Left Ventricular Mechanical Dyssynchrony With Radial Strain By Speckle-tracking Best Predicts Response To Cardiac Resynchronization Therapy
Background: Recently, 2-dimensional strain by speckle tracking imaging has emerged as a new technology for assessment of myocardial deformation in three dimensions: radial, circumferential and longitudinal. The current study evaluates which type of deformation study can best identify left ventricular mechanical dyssynchrony (LVMD) and predicts response to cardiac resynchronization therapy (CRT).
Methods: One-hundred fifty-two consecutive patients underwent echocardiographic study before implantation of the CRT device and at 6 months follow-up. Radial (RS) and circumferential (CS) strains were applied to midventricular short axis views; difference in time to peak systolic strain value between anteroseptal-to-posterior walls was used to study LVMD. Longitudinal strain (LS) was applied to apical 4-chamber views and LVMD was calculated as the difference between basal septum-to-basal lateral walls. Patients with a decrease of LV end-systolic volume ≥15% at 6 months follow-up were considered responders.
Results: After 6 months of CRT, 85 pts (56%) showed response to CRT. Compared to non-responders, responders had significant more LVMD when it was assessed by RS (212±146 ms vs. 127±108 ms; p<0.001), whereas there were no differences with neither CS nor LS (Table⇓). With RS, the optimal cut-off value to predict response to CRT was identified at a time-difference value of ≥130 ms yielding a sensitivity of 83% and a specificity of 71%.
Conclusions: Radial strain by speckle-tracking imaging is a useful tool to assess LVMD and best predicts echocardiographic response to CRT.