Myocardial bridging is associated with coronary atherosclerosis in the segment proximal to the site of bridging.

Background: Myocardial bridging is a common finding on multi-detector computed tomography (MDCT). The segment proximal to a myocardial bridge is frequently atherosclerotic, although the tunneled segment is spared. This study aimed to investigate whether myocardial bridging identified by MDCT is an independent risk factor for coronary atherosclerosis.

Methods And Results: Patients (n=188) with suspected coronary disease underwent MDCT using a 40-detector or 64-detector instrument. We reviewed the baseline characteristics (age, body mass index, smoking history, presence of hypertension, dyslipidemia, and diabetes mellitus) and the results of MDCT angiography. Two radiologists evaluated the coronary artery for myocardial bridging and coronary atherosclerosis and made a diagnosis by consensus. Significant independent risk factors for coronary atherosclerosis were investigated by multivariate logistic regression analysis. We identified 50 bridges in the middle segment of the left anterior descending artery (LAD). There were no patients with significant stenosis in the tunneled segment. Multivariate analysis showed that age, diabetes mellitus, and myocardial bridging in the mid-LAD were significantly associated with coronary atherosclerosis in the proximal LAD (p<0.05). Age, diabetes mellitus, and the absence of myocardial bridging in the mid-LAD were significantly associated with coronary atherosclerosis in the mid-LAD (p<0.05).

Conclusion: The segment proximal to a segment with myocardial bridging is frequently involved in atherosclerosis, although the tunneled segment is spared. Myocardial bridging in the mid-LAD is an independent risk factor for coronary atherosclerosis in the proximal LAD.