Comparison of myocardial deformation and velocity dyssynchrony for identification of responders to cardiac resynchronization therapy

Aims It is unclear whether myocardial velocity or deformation indices of dyssynchrony are better at predicting response to cardiac resynchronization therapy (CRT). Therefore, two indices of left ventricular (LV) dyssynchrony based on myocardial velocity and deformation were compared to predict success of CRT. Methods and results Sixty patients with dilated cardiomyopathy, New York Heart Association class III–IV, LV ejection fraction (EF) ≤35%, QRS >120 ms underwent CRT. The standard deviation of the averaged time-to-peak longitudinal negative strain (Tɛ-SD) and positive systolic velocity (Tv-SD) of 12 LV segments were calculated before and after 6 months of CRT. Responders were defined at month 6 by ≥20% EF increase and/or ≥15% end-systolic volume (ESV) decrease with respect to baseline. On univariable analysis, baseline Tɛ-SD and Tv-SD were both significantly associated with CRT response; however, the area under the receiver operating characteristic curve was better for Tɛ-SD. On bivariable analysis, only Tɛ-SD retained an independent prognostic value for CRT response. Results of the analysis did not change when the logistic models were adjusted for aetiology. Conclusion Baseline dyssynchrony of longitudinal myocardial peak deformation (Tɛ-SD) appears to be better than dyssynchrony of longitudinal myocardial peak systolic velocities (Tv-SD) for the identification of CRT responders.