Evaluation of Myocardial Bridging of the Left Anterior Descending Coronary Artery by 64-Slice Multidetector Computed Tomographic Angiography

The purpose of this study was to use the unique characteristics of multidetector computed tomographic coronary angiography to evaluate the prevalence and characteristics of myocardial bridging (MB) in a large series of patients and to assess the relation between atherosclerosis and MB. Three hundred consecutive coronary angiograms obtained by 64-slice multidetector computed tomography were evaluated retrospectively. For comparison of symptoms and concomitant atherosclerosis, 245 patients were included in the study and categorized into group 1 (n = 108) with MB and group 2 (n = 137) with no MB in the left anterior descending coronary artery (LAD). Axial and multiplanar reformatted images of all arteries were analyzed for the presence of measurable obstructive coronary disease (>25% stenosis) and minor luminal (<25% stenosis) calcified and noncalcified plaque and for MB in the LAD. Longitudinal and cross-sectional views were used for MB measurements. MB was found in 44% of patients (108 of 245) and was present equally in men and women (45% and 41%, p = NS). The mid LAD was the most common location (66%, p <0.001). There were no atherosclerotic lesions within the MB segments. The presence of MB did not influence the presence or severity of atherosclerotic lesions in the nonbridged segments of the LAD. In conclusion, MB as demonstrated by 64-slice multidetector computed tomographic coronary angiography is more common than previously reported by coronary angiography. The bridged segment appears to be free of atherosclerosis.