Quantitative left ventricular mechanical dyssynchrony by magnetic resonance imaging predicts the prognosis of dilated cardiomyopathy

Left ventricular (LV) dyssynchrony is believed to be associated with the prognosis of dilated cardiomyopathy (DCM) mainly assessed by echocardiography. This study sought to explore whether quantitative LV mechanical dyssynchrony by cardiovascular magnetic resonance imaging (CMR) tissue feature tracking could predict the prognosis of DCM.Patients undergoing CMR between January 2016 and December 2017 were reviewed to identify DCM patients. Quantitative LV mechanical dyssynchrony was assessed by CMR strain analysis. The outcomes of these DCM patients were followed up. The association between LV mechanical dyssynchrony and outcomes was analyzed by Cox proportional regression analysis.A total of 417 patients with DCM were enrolled. At a median follow-up of 57 months, 109 patients reached endpoints: 19, sudden cardiac death; 34, heart failure death; 41, heart transplantation; 9, malignant ventricular arrhythmias; 2, LV assist devices; and 4, appropriate shocks of defibrillators. After adjustment for confounding variables, the 16-segment standard deviation of the time-to-peak radial strain (16SDTTPRS) (HR, 1.932 [95% CI: 1.079, 3.461]; P = 0.027), LV end-diastolic diameter index (HR, 1.049 [95% CI: 1.020, 1.080]; P = 0.001), NYHA classes (HR, 2.131 [95% CI: 1.597-2.844]; P < 0.001) and late gadolinium enhancement (HR, 3.219 [95% CI: 2.164, 4.787]; P < 0.001) were independently associated with composite endpoints.The quantitative LV mechanical dyssynchrony parameter 16SDTTPRS derived from CMR was independently associated with adverse outcomes in patients with DCM.