title: Relationship between myocardial bridges and reduced coronary atherosclerosis in patients with angina pectoris.
abstract: BACKGROUND
  A myocardial bridge (MB) is a band of myocardium covering a coronary artery segment, typically located in the left anterior descending coronary artery (LAD). Bridged segments of the coronary artery are isolated from the influence of perivascular adipose tissue. The aims of this study were to investigate the relationship between MBs and atherosclerosis in bridged LAD segments and to evaluate whether perivascular adipose tissue is involved in this relationship.
  
  
  METHODS
  MBs were identified in the coronary arteries of patients referred for diagnostic cardiac CT. The calcium score of MBs of the LAD or, in patients without LAD-MBs, of a corresponding LAD segment at the same distance from its origin and over the same length was measured.
  
  
  RESULTS
  Of 128 patients, 56 (44%) had in total 73 MBs. The mean MB length was 22 ± 14 mm and the median MB thickness was 0.8mm (interquartile range 0.3-2.1mm). MBs in the LAD were present in 40 patients (31%). The calcium score was 0 in 95% of the LAD segments with MBs compared with 52% of the corresponding LAD segments without MBs. The association between LAD-MBs and calcium score (OR 0.06, 95% CI 0.01-0.25) was not influenced by age and gender, but was attenuated by local perivascular adipose tissue thickness (OR 0.35, 95% CI 0.04-2.70).
  
  
  CONCLUSIONS
  Coronary artery segments covered with an MB have a lower calcium score than segments without an MB. The association between MBs and calcium scores was influenced by local perivascular adipose tissue thickness.
authors.affiliation: Department of Vascular Medicine, University Medical Center Utrecht, The Netherlands.
authors.forename: Sandra N
authors.initials: SN
authors.lastname: Verhagen
authors.forename: Annemarieke
authors.initials: A
authors.lastname: Rutten
authors.forename: Matthijs F
authors.initials: MF
authors.lastname: Meijs
authors.forename: Ivana
authors.initials: I
authors.lastname: Isgum
authors.forename: Maarten J
authors.initials: MJ
authors.lastname: Cramer
authors.forename: Yolanda
authors.initials: Y
authors.lastname: van der Graaf
authors.forename: Frank L J
authors.initials: FL
authors.lastname: Visseren
mesh_terms: D000368:Aged; D000787:Angina Pectoris / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000453:epidemiology* / Q000517:prevention & control; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D054084:Myocardial Bridging / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D009426:Netherlands / Q000453:epidemiology; D011859:Radiography; D012307:Risk Factors