ABSTRACT
BACKGROUND AND OBJECTIVES: Strain imaging has already been shown to quantify regional myocardial function in both acute ischemic myocardium and infarcted myocardium. We proposed that strain imaging could differentiate deformation of normal and ischemic myocardium that are without regional wall motion abnormality, as assessed by conventional echocardiography. The aim of this study is to determine the diagnostic value of strain imaging for the detection and localization of coronary lesions in patients with chest pain, but they are without apparent wall motion abnormalities. SUBJECTS AND METHODS: Strain imaging for advanced wall motion analysis was performed in 179 patients with suspicious stable angina (SA) and in 94 patients with suspicious acute coronary syndrome (ACS) prior to coronary angiography. All the patients had normal conventional wall motion scoring based on the standards of the American Society of Echocardiography. Longitudinal strain was measured in 3 apical views, and assessments of the strain value for individual segments with using an 18-segment division of the left ventricle were performed to determine the average strain value. Marked heterogeneity of strain was considered abnormal, and significant coronary artery disease was considered present if stenosis above 70% was noted on the quantitative angiography. RESULTS: Eighty (78%) of the 103 patients with SA and 18 (56%) of the 32 patients with ACS and who showed constant systolic strain throughout the left ventricular wall had normal or minimal coronary lesions. Fifty-one (67%) of the 76 patients with SA and 53 (85%) of the 62 patients with ACS and marked heterogeneity of strain had angiographically significant coronary stenosis. The receiver-operating characteristic (ROC) analysis of the peak systolic strain yielded that the ROC-area of peak systolic strain for the left anterior descending artery territory was 0.79 (95% CI 0.72-0.84), this was 0.87 (95% CI 0.79-0.91) for the left circumflex artery territory and 0.89 (95% CI 0.79-0.93) for the right coronary artery territory. CONCLUSION: Ultrasound-based strain imaging demonstrates a strong correlation with coronary angiography and it has potential as a noninvasive diagnostic tool for detecting coronary artery stenosis in patients with chest pain, but who are without apparent wall motion abnormalities on conventional echocardiography.