Evaluation of Left Atrial Strain Parameter in Coronary Artery Stenosis: A New Tool to Predict LCX Stenosis

Speckle tracking echocardiography (STE) based on frame-to-frame tracking of acoustic speckles is a novel angle-independent method, used for evaluating myocardial deformation and recently to assess left atrium (LA) function. To the best of our knowledge, there is no investigation evaluating the predictor role of LA strain parameters in detection of coronary artery stenosis in ischemic heart disease. In this study, we assessed this parameter for predicting the culprit artery in patients underwent selective coronary angiography (SCA) in Mashhad, Iran. This was a case-control study, which was performed in Imam Reza and Ghaem Hospitals in Mashhad, Iran between 2017 and 2018 in patients referred for SCA. Subjects with two or three- vessel diseases were  excluded .Sixty-five cases were included in the study and divided into four groups according to the vessel involved : Group (1): normal coronary artery subjects (n=36); group (2): patients with left anterior descending (LAD) artery stenosis (n=12); group (3): patients with left circumflex artery (LCX) stenosis (n= 7) and group 4: patients with right coronary artery (RCA) stenosis (n=10). Patients underwent routine TTE and Speckle Tracking Imaging. The mean age of participants was 56.72± 10.69 years old. The male/female ratio was 0.96. Mean absolute value of LA strain was 24.74% in normal subjects, while in groups with stenotic coronary artery disease, less values were defined as 18.63%, 16.03% and 19.05%, respectively (p value=0.05). The amounts of left ventricle end systolic volume (LVESV), LV global longitudinal strain (GLS) and Em of septal annulus were significantly different between normal group and those with LCX stenosis. Among different echocardiographic parameters, LA strain, LVESV and Em of septal annulus were defined as predictors of LCX occlusion with regression analysis. LA strain in subjects with coronary artery stenosis was lower than the strain in normal group and could predict isolated LCX occlusion.