|| Checking for direct PDF access through Ovid
Purpose: The left ventricular (LV) wall of the heart comprises three myocardial layers. The subendocardial layer is most susceptible to ischemic injury. We hypothesised that patients with coronary artery disease (CAD) and significant coronary artery stenosis have reduced subendocardial function assessed by strain compared to patients without stenoses.Methods: Fifty-one patients with suspected non-ST elevation myocardial infarction (NSTEMI) and unstable angina pectoris (UAP) were included. Thirty of these patients had significant stenosis in one or more coronary arteries while 21 patients did not have significant stenosis and served as controls. Peak systolic longitudinal subendocardial, subepicardial and transmural (including all cardial layers) strain were assessed by 2D speckle tracking echocardiography in a 16 LV segments model and averaged to global longitudinal strain subendocardially, subepicardially and transmurally.Results: Patients with significant coronary artery stenosis had worse overall myocardial function compared to patients without significant stenosis (Table). Subendocardial strain (-17.6 ± 2.6%) was significantly greater than subepicardial strain (-13.3 ± 1.9%, p<0.001) in the whole study population. The absolute difference between subendocardial and subepicardial strain was lower in patients (Δ3.8%) than in controls (Δ4.9%, (p=0.02). This reflects more pronounced ischemic injury in the subendocardial layer in patients with significant stenoses. In a ROC analysis, subendocardial strain had the best AUC 0.83 (95% CI 0.71-0.95) to identify significant coronary stenosis, while transmural strain showed 0.82 (95% CI 0.70-0.94) and subepicardial strain 0.74 (95%CI 0.71-0.95).Conclusions: Subendocardial function was more affected in NSTEMI and UAP patients with significant coronary artery stenosis compared to subepicardial function. Assessment of layer-specific strain echocardiography might identify NSTEMI and UAP patients with significant coronary artery stenosis.