Rest global longitudinal 2D strain to detect coronary artery disease in patients undergoing stress echocardiography: a comparison with wall-motion and coronary flow reserve responses.

Myocardium subtended by obstructive coronary artery disease (CAD) may show reduced left ventricle (LV) global longitudinal strain (GLS), as well as early systolic lengthening (ESL) before shortening; these can be measured at rest and may predict obstructive CAD. This study investigated whether baseline resting LV longitudinal strain measurements may be able to detect significant CAD in patients undergoing stress echocardiography (SE) and coronary angiography, who have normal resting wall motion. We selected patients with a clinical indication of coronary angiography who were previously referred for SE. Patients with known CAD, rest wall-motion (WM) abnormalities, or rhythm/conduction abnormalities were excluded. Speckle tracking strain analyses were retrospectively performed on digitally archived 2D video-loops, using vendor independent software. Peak GLS and duration of ESL were recorded. Diagnostic accuracy of each parameter to predict obstructive (≥50%) CAD was assessed and multivariate logistic regression models fitted and compared. Eighty-two patients were enrolled and 49 had significant CAD by quantitative angiography. Patients with CAD were more often male (P=0.01) and more frequently presented with typical angina (P<0.01). Among rest and stress variables, GLS showed a Youden index of 0.665, while SE WM assessment showed a Youden index of 0.599. These were the only two parameters that remained predictive in multivariate analyses. In conclusion, rest GLS demonstrated comparable accuracy with stress-echo data for prediction of angiographically obstructive CAD; it also added significant CAD prediction when combined with clinical data, similar to SE WM assessment.