Abstract 12745: Is Myocardial Bridging Truly Benign? Impact of Myocardial Bridging Induced Arterial Compression on Atherosclerotic Plaque Formation
Introduction: A myocardial bridge (MB) that partially covers the left anterior descending coronary artery (LAD) sometimes leads to atherosclerotic plaque formation proximal to the MB because of hemodynamic disturbance. However it is not clear which morphologic properties of the MB relate to the extent of atherosclerosis. Hypothesis: We assessed the hypothesis that a MB detected by intravascular ultrasound (IVUS) potentially impacts atherosclerosis among angina patients.
Methods: IVUS images were analyzed in de novo coronary lesions. MB was defined as an echolucent muscle band (halo) partially surrounding the artery. The MB length, halo thickness, arterial compression, the distance from LAD ostium to MB, maximum plaque burden up to 20 mm proximal to the MB entrance (Max PB Prox) and within the MB (Max PB MB) were measured. Clinical risk factors and morphologic properties with a p-value<0.20 on univariate analysis were inserted into multivariate models.
Results: IVUS identified 96 MB segments (age: median 53, range 20-77; male: 36%): 21±13 mm in MB length, 0.7±0.6 mm in halo thickness and 22±12% in arterial compression. Max PB Prox was significantly greater than Max PB MB (39±15 vs. 22±7%, p<0.001). Arterial compression had a significant positive correlation to Max PB Prox (r=0.265, p=0.009), but not to Max PB MB. When focusing on the younger adults (age ≤ median) with ≤ one coronary risk factor, the correlation between arterial compression and Max PB Prox showed an even stronger relationship (r=0.565, p<0.001). In contrast, there was no correlation between the other morphologic properties and either measures of Max PB. In multivariate analysis, arterial compression was independently associated with Max PB Prox (Table).
Conclusion: Arterial compression correlates with atherosclerotic plaques at the segment proximal to the bridge. Patients with an MB and strong arterial compression may require careful follow-up even if patients are young and have few risk factors.
- © 2012 by American Heart Association, Inc.