Integrated analysis of cardiac tissue structure and function for improved identification of reversible myocardial dysfunction

Abstract

Background: Myocardial deformation imaging and contrast-enhanced cardiac magnetic resonance imaging (ceMRI) have been used to define myocardial viability in ischemic left ventricular dysfunction. This study evaluated the incremental predictive value of an integrated analysis of function and tissue structure for functional improvement after revascularization therapy.

Methods: In 59 patients with ischemic left ventricular dysfunction, myocardial viability was defined by pixel-tracking-derived myocardial deformation imaging and ceMRI to predict recovery of function at 9+/-2 months follow-up after revascularization. For each left ventricular segment in a 16-segment model, peak systolic radial strain was determined from parasternal two-dimensional echocardiographic views using an automatic frame-by-frame tracking system of natural acoustic echocardiographic markers, and extent of hyperenhancement using ceMRI. Five categories were generated for each parameter, allowing subsequent combination. The predictive power for segmental improvement in function was determined for each of the modalities as well as the combination of both.

Results: From 512 dysfunctional segments at baseline, 251 segments (49%) demonstrated functional recovery. The accuracy to predict functional recovery was area under curve (AUC)=0.846 for peak systolic radial strain and AUC=0.834 for extent of hyperenhancement. A combination of both parameters improved the predictive accuracy compared with hyperenhancement alone, AUC=0.861, P value of less than 0.001. In sequential Cox models, the predictive power for segmental functional recovery of extent of hyperenhancement alone (chi model 171.0, P<0.001), or peak systolic radial strain alone (chi model 205.9, P<0.001), was strengthened by a combination of both parameters (chi model 248.5, P<0.001). The advantage of image integration was particularly strong in those segments with intermediate degree of late enhancement (DeltaAUC=0.065, P<0.001).

Conclusion: Integration of advanced information on myocardial function using deformation imaging and findings on myocardial tissue structure increases the accuracy to identify reversible myocardial dysfunction.