title: Association of coronary shear stress with endothelial function and vascular remodeling in patients with normal or mildly diseased coronary arteries.
abstract: BACKGROUND
  The relationship between coronary remodeling, shear stress and endothelial function remains unclear.
  
  
  OBJECTIVE
  The present study investigated the effects of mechanical factors on structure and function of epicardial coronary arteries.
  
  
  METHODS
  Patients (group 1: %area stenosis<40%, n=55; or group 2: %area stenosis>or=40%, n=17) with a discrete mildly stenotic lesion (%diameter stenosis<30%) underwent intravascular ultrasound examination of the left anterior descending coronary artery for determination of vessel area, lumen area, plaque area, cross-sectional areas at reference segments, and remodeling index (the ratio of vessel area at the culprit lesion to vessel area at the proximal reference site). Further, vascular reactivity was examined using intracoronary administration of acetylcholine, papaverine, and nitroglycerin.
  
  
  RESULTS
  Vessel area significantly correlated with plaque area in both groups (r=0.65, P<0.0001 and r=0.85, P<0.0001). Group 1 showed significantly greater acetylcholine-induced percentage changes in coronary blood flow (67+/-70 vs. 16+/-75%, P<0.05) and coronary artery diameter (-7+/-18 vs.-32+/-31%, P<0.01) and also significantly smaller coronary wall shear stress (65+/-27 vs. 81+/-32 dynes/cm, P<0.05) than group 2. The percentage increase in coronary blood flow induced by acetylcholine was significantly and positively correlated with remodeling index in group 1 (r=0.64, P<0.0001) but not in group 2 (r=-0.03, P=0.90) and was also significantly and positively correlated with coronary wall shear stress in group 1 (r=0.46, P<0.001) but not in group 2 (r=-0.33, P=0.19).
  
  
  CONCLUSIONS
  Endothelium-dependent vasodilation in the resistance coronary artery correlates with remodeling via increased wall shear stress when target lesions %area stenosis is <40%.
authors.affiliation: Department of Cardiovascular, Respiratory and Metabolic Medicine, Graduate School of Medicine, Kagoshima University, Kagoshima, Japan.
authors.forename: Keishi
authors.initials: K
authors.lastname: Saihara
authors.forename: Shuichi
authors.initials: S
authors.lastname: Hamasaki
authors.forename: Hideki
authors.initials: H
authors.lastname: Okui
authors.forename: Sadatoshi
authors.initials: S
authors.lastname: Biro
authors.forename: Sanemasa
authors.initials: S
authors.lastname: Ishida
authors.forename: Akiko
authors.initials: A
authors.lastname: Yoshikawa
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Kataoka
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Ninomiya
authors.forename: Etsuko
authors.initials: E
authors.lastname: Mizoguchi
authors.forename: Tomoko
authors.initials: T
authors.lastname: Ichiki
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Otsuji
authors.forename: Chuwa
authors.initials: C
authors.lastname: Tei
mesh_terms: D000328:Adult; D000368:Aged; D001775:Blood Circulation; D003324:Coronary Artery Disease / Q000473:pathology / Q000503:physiopathology*; D023921:Coronary Stenosis / Q000503:physiopathology*; D003331:Coronary Vessels / Q000473:pathology / Q000503:physiopathology*; D004730:Endothelium, Vascular / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013314:Stress, Mechanical; D014664:Vasodilation; D020257:Ventricular Remodeling / Q000502:physiology*