title: Endothelial function and hemorheological parameters modulate coronary blood flow in patients without significant coronary artery disease.
abstract: BACKGROUND
  Coronary (micro)vascular resistance is regulated by the complex interplay of several factors. Two potentially important determinants include endothelial function and the rheological properties of blood. However, their impact on the control of the coronary resistance vasculature is poorly understood.
  
  
  METHODS
  The corrected Thrombolysis In Myocardial Infarction frame count (TIMIfc, an index of coronary flow velocity), conduit artery endothelial function, intima-media thickness of the common carotid artery and complete blood counts were measured in 145 patients undergoing elective coronary angiography. Patients with obstructive coronary artery disease or systemic conditions thought to be associated with microvascular disease were excluded from the analysis.
  
  
  RESULTS
  There was a strong correlation between the TIMIfc measured in the three main coronary artery distributions (R values between 0.71 and 0.85, P < 0.00001). The TIMIfc was higher in males (P < 0.05), but there was no association with traditional risk factors for coronary artery disease (all P > 0.1). There was a correlation between TIMIfc and L-FMC, a parameter of resting endothelial function (R = 0.33, P < 0.0005). TIMIfc also correlated with mean platelet volume (a marker of platelet activation, R = 0.33, P < 0.001), and hematocrit (R = 0.33, P = 0.0002). There was no correlation between TIMIfc and carotid intima-media thickness and the degree of coronary atherosclerosis. Logistic regression analysis showed that L-FMC and hemorheological variables may explain as much as 19% of the variability in TIMIfc.
  
  
  CONCLUSIONS
  Resting peripheral endothelial function, as well as parameters of platelet function, correlate with coronary TIMIfc. These data emphasize the existence of an association between endothelial function, hemorheological variables and coronary blood flow velocity.
authors.affiliation: Department of Cardiology, University Medical Center Mainz, Mainz, Germany. tommaso.gori@unimedizin-mainz.de
authors.forename: Tommaso
authors.initials: T
authors.lastname: Gori
authors.forename: Ana
authors.initials: A
authors.lastname: Damaske
authors.forename: Selina
authors.initials: S
authors.lastname: Muxel
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Radmacher
authors.forename: Federica
authors.initials: F
authors.lastname: Fasola
authors.forename: Sarina
authors.initials: S
authors.lastname: Schaefer
authors.forename: Massimo
authors.initials: M
authors.lastname: Fineschi
authors.forename: Sandro
authors.initials: S
authors.lastname: Forconi
authors.forename: Friedrich
authors.initials: F
authors.lastname: Jung
authors.forename: Thomas
authors.initials: T
authors.lastname: Münzel
authors.forename: John D
authors.initials: JD
authors.lastname: Parker
mesh_terms: D000368:Aged; D001783:Blood Flow Velocity; D059168:Carotid Intima-Media Thickness; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000097:blood / Q000000981:diagnostic imaging / Q000503:physiopathology; D003326:Coronary Circulation / Q000502:physiology*; D004730:Endothelium, Vascular / Q000000981:diagnostic imaging / Q000502:physiology* / Q000503:physiopathology; D005260:Female; D018056:Hemorheology; D006801:Humans; D008297:Male; D015539:Platelet Activation; D012307:Risk Factors