Prognostic Value of Left Ventricular Standardized Mechanical Dispersion Derived From Cardiac Magnetic Resonance Feature Tracking in Patients with Dilated Cardiomyopathy

To evaluate the prognostic value of standardized left ventricular mechanical dispersion (sLVMD) for major adverse cardiovascular events (MACEs) in patients with dilated cardiomyopathy (DCM) and to assess its incremental contribution to predictive model performance. This study included patients with DCM who underwent cardiac magnetic resonance (CMR). Myocardial strain was assessed using CMR feature tracking. Left ventricular mechanical dispersion (LVMD) was defined as the standard deviation of time-to-peak strain of the 16 segments in radial (RMD), circumferential (CMD), and longitudinal (LMD) directions. sLVMD was calculated as LVMD/cardiac cycle duration (seconds), including sRMD, sCMD and sLMD. MACEs included cardiac death, hospitalization for heart failure, and malignant arrhythmia. During a median follow-up period of 28.0 months, 83 patients reached the study endpoints. Kaplan-Meier analysis showed that elevated sLVMD was associated with an increased incidence of MACEs (all log-rank P < 0.001). Multifactorial Cox regression identified sLVMD as an independent predictor of MACEs (sRMD: hazard ratio [HR]) 1.008; sCMD: HR 1.007; sLMD: HR 1.005; all P < 0.05). The C-statistic of the model incorporating sLVMD and conventional clinical and imaging risk factors for predicting MACEs was 0.713 (95% CI [confidence interval], 0.649–0.777; P = 0.003), which represented a significant improvement compared with the model including LVMD and the same conventional factors (C-statistic, 0.678; 95% CI, 0.614–0.742; P = 0.018). sLVMD assessed by CMR serves as a significant independent predictor of MACEs in patients with DCM and provides valuable incremental information for prognostic assessment.