Incremental Value of Three-dimensional Speckle-tracking Echocardiography for Evaluating Left Ventricular Systolic Function in Patients with Coronary Slow Flow.

The purpose was to evaluate left ventricular (LV) systolic function in patients with coronary slow flow (CSF), and compared the incremental values of 3-dimensional (3D) speckle-tracking echocardiography (STE). Seventy-three patients with CSF and 60 control subjects were enrolled. CSF was diagnosed during coronary angiography. Two-dimensional (2D) and 3D global strain were measured using STE. Sex, mitral E, 2D GLS, and all 3D strain parameters were independent predictors of CSF. Combination of sex, mitral E, and 3D GTS had the highest area under the curve (AUC) for identifying CSF (AUC, 0.81; P < 0.001). Integrated discrimination index (IDI) improved adding 3D GTS to the combined sex and mitral E model (IDI = 0.12, P = 0.01) or 2D GLS model (IDI = 0.14, P < 0.001). LV systolic function was impaired in CSF patients. 3D GTS had an independent and incremental value for predicting CSF compared with 2D echocardiography.