Role of myocardial bridges in arterial remodeling and atherosclerosis development

Myocardial bridges represent segments of coronary arteries partially covered by myocardial muscle fibers. Although myocardial bridges were previously thought to be rare, recent studies indicate an increase in their prevalence, which has been associated with acute coronary syndromes, arrhythmias, myocardial infarction, and even sudden cardiac death. Some authors suggest that myocardial bridges may contribute to the formation of atherosclerotic plaques in the proximal part of the coronary arteries. Autopsy findings also demonstrate increased atherosclerotic plaque formation at sites of arterial obliteration, suggesting a shared pathogenic mechanism in the intima-media layer. This review summarizes current knowledge regarding the role of myocardial bridges in vascular remodeling and atherosclerosis progression, while identifying gaps requiring further investigation. The authors conducted a search of publications in the electronic databases PubMed, Google Scholar, and eLibrary using the following keywords: “atherosclerosis and myocardial bridges”, “myocardial bridges and cardiovascular diseases”, “pathophysiology of myocardial bridges”, “visualization of the cardiovascular system”, “myocardial bridges”. All works published between 1951 and 2024 were included. The obstructive mechanism involves compression of the intramural segment of the coronary artery by myocardial tissue during systole. Hemodynamic conditions created by myocardial bridges typically feature elevated wall shear stress due to the narrowing of the arterial lumen during systole, thereby minimizing plaque formation within the bridge itself. However, proximal to the myocardial bridges, wall shear stress decreases, creating favorable conditions for atherosclerotic plaque development. Myocardial bridges influence the thickness of the intima and the area of the arterial lumen, as well as the segments located proximally and distally. The location, thickness, and length of myocardial bridges directly affect the degree of obstruction and intimal hypertrophy. Vascular remodeling under mechanical forces plays a crucial role in maintaining vessel function, and its disruption can lead to cardiovascular disease.