The relationship between myocardial bridge type and proximal stenosis in hypertensive patients

Background: Myocardial bridges (MBs) are a congenital abnormality in which a part of the coronary artery is tunneled or immersed in the myocardium, most commonly found in the left anterior descending (LAD) artery. In the artery proximal to the bridge, there is formation of atherosclerosis causing stenosis. However, the tunneled and distal part of the artery is free from atherosclerosis. Objective: This study will investigate the relationship between MB type and proximal stenosis in hypertensive patients. Methods: A total of 140 MB patients were selected form Nanjing Hospital database, all aged between 31 and 91 years. A total of 33 were further excluded from the study. The data of the remaining 107 patients, including the type of bridge, length, depth, blood pressure, cholesterol level, and artery involved, were all taken. The Pearson's Chi-square test was done to compare the relationship between the bridge type and degree of stenosis in the artery proximal to the bridge in hypertensive patients. Results: Among those 107 patients, 69 (64.4%) had a superficial bridge and 38 (35.5%) had a deep bridge. The P value of the superficial bridge group was (0.993), while that of the deep bridge group was (0.580). Conclusion: In this study, superficial bridges were the most common form of MB and the most common artery involved was the (middle segment of) LAD. There were no signs of atherosclerosis in the MB (or tunneled) arteries or the distal parts. This study found no link between MB type and proximal stenosis in hypertensive patients.