Interatrial Septal Thickness as a Predictor of the Presence and Severity of Coronary Artery Disease

Background: Coronary artery disease (CAD) is the most prevalent cardiovascular disease. Even though the definitive diagnosis of CAD is by invasive coronary angiography (CAG), various imaging modalities and their advances have led to the evolution of noninvasive parameters such as epicardial adipose tissue (EAT), which could help in prediction of CAD. However, despite having a good association with CAD, the quantification of EAT is unreliable. The adipose tissue of the atrial septum is considered a surrogate of EAT. We aimed to study the association of interatrial septal thickness (IST) measured by echocardiography with the severity of CAD. Methods: A total of 200 patients with a probable diagnosis of CAD undergoing echocardiography and CAG were studied. The IST was measured using two-dimensional transthoracic echocardiography. The presence or absence, the extent, and the severity of CAD were known by CAG. Relevant statistical analysis was done to look for the association of IST with CAD. Results: The mean age of the population was 51.97 ± 10.19 years and the mean IST was 8.02 ± 3.2 mm. Of the baseline characteristics, age, hypertension, and history of CAD were found to be significantly associated with IST. There was significant association of IST with the presence of any extent of CAD. On multivariate regression analysis, IST was found to be an independent predictor of the presence of CAD, having positive association. A positive correlation ( r = 0.868) was found between IST and the severity of CAD. The receiver operating characteristic curve analysis showed that IST >5.7mm predicted the presence of any CAD with a sensitivity of 78.6% and a specificity of 100%. Conclusion: IST, a measure of the adipose tissue of atrial septum, was found to be an independent predictor of the presence and severity of CAD.