Myocardial deformation imaging based on ultrasonic pixel tracking to identify reversible myocardial dysfunction.

OBJECTIVES This study evaluated the predictive value of myocardial deformation imaging for improvement in cardiac function after revascularization therapy in comparison with contrast-enhanced cardiac magnetic resonance imaging (ceMRI). BACKGROUND Myocardial deformation imaging allows analysis of myocardial viability in ischemic left ventricular dysfunction. METHODS In 53 patients with ischemic left ventricular dysfunction, myocardial viability was assessed using pixel-tracking-derived myocardial deformation imaging and ceMRI to predict recovery of function at 9 +/- 2 months follow-up. For each left ventricular segment in a 16-segment model, peak systolic radial strain was determined from parasternal 2-dimensional echocardiographic views using an automatic frame-by-frame tracking system of natural acoustic echocardiographic markers (EchoPAC, GE Ultrasound, Horton, Norway), and the relative extent of hyperenhancement using ceMRI. RESULTS Of 463 segments with abnormal baseline function, 227 showed regional recovery. Compared with segments showing functional improvement, those that failed to recover had lower peak radial strain (15.2 +/- 7.5% vs. 22.6 +/- 6.3%; p < 0.001) and a greater extent of hyperenhancement (56 +/- 29% vs. 14 +/- 17%; p < 0.001). Using a cutoff of 17.2% for peak systolic radial strain, functional recovery could be predicted with high accuracy (sensitivity 70.2%, specificity 85.1%, area under the curve 0.859, 95% confidence interval 0.825 to 0.893). The predictive value was similar to that of hyperenhancement by ceMRI (sensitivity 71.6%, specificity 92.1%, area under the curve 0.874, 95% confidence interval 0.840 to 0.901, at a cutoff of 43% hyperenhancement). CONCLUSIONS Myocardial deformation imaging based on frame-to-frame tracking of acoustic markers in 2-dimensional echocardiographic images is a powerful novel modality to identify reversible myocardial dysfunction.