To evaluate the global and local systolic function of left ventricular myocardium in patients with left anterior descending coronary artery (LAD) stenosis and to explore its clinical value in early diagnosis of coronary heart disease (CHD).

From November 2016 to June 2017, 123 patients with diagnosed with suspected CHD and confirmed with simple LAD stenosis by coronary angiography (case group) and 32 patients without obvious stenosis (control group) at Shanxi Cardiovascular Hospital were included. According to the results of LAD coronary angiography, the 123 patients were divided into four groups: A (stenosis degree≤30%), B (30%<stenosis degree≤50%), C (50%<stenosis degree≤75%), and D (75%<stenosis degree≤100%). All patients underwent ultrasound examination before coronary angiography, and conventional ultrasound parameters and strain parameters were measured. Strain parameters included global longitudinal strain of the endo-myocardium (GLSendo), global longitudinal strain of the mid-myocardium (GLSmid), global longitudinal strain of the epi-myocardium (GLSepi), territorial longitudinal strain of the endo-myocardium (TLSendo), territorial longitudinal strain of the mid-myocardium (TLSmid), territorial longitudinal strain of the epi-myocardium (TLSepi), global transmural gradient ?GLS (GLSendo-GLSepi), and territorial transmural gradient ?TLS (TLSendo-TLSepi). Statistical analyses were performed to compare the longitudinal stratified strain parameters among groups, and ROC curves were plotted to predict the left anterior descending branch stenosis.

GLSendo, GLSmid, GLSepi, TLSendo, TLSmid, and TLSepi in each group decreased in turn (all P<0.001); there was no significant difference in ?GLS or ?TLS between groups (P>0.05); there was no significant difference in longitudinal strain parameters of the myocardium among the control group, group A, and group B (P>0.05). Compared with the control group, group A, and group B, GLSendo, GLSepi, TLSendo, TLSmid, and TLSepi in group C and GLSendo, GLSmid, GLSepi, TLSendo, TLSmid, and TLSepi in group D decreased (P<0.05), and the longitudinal strain parameters between groups C and D were significantly different (all P<0.05). The area under the ROC curve was 0.81 when TLSendo was used to diagnose LAD stenosis (50%<stenosis degree≤75%), and the sensitivity and specificity were 61.5% and 88.5%, respectively, when the cut-off value was -23.97%. The area under the ROC curve was 0.88 when TLSepi was used to diagnose LAD stenosis (75%<stenosis degree≤100%), and the sensitivity and specificity were 86.8% and 81.6%, respectively, when the cut-off value was -16.44%.

Longitudinal stratified strain technique can quantitatively evaluate the global and regional systolic function of left ventricular myocardium and myocardial ischemia in CHD patients with different degrees of LAD stenosis , and it has appreciated value for the early diagnosis of CHD.