title: Prevalence of coronary blood flow reserve abnormalities among patients with nonobstructive coronary artery disease and chest pain.
abstract: OBJECTIVE
  To determine the prevalence of abnormalities in endothelium-dependent and endothelium-independent coronary flow reserve among patients with non-obstructive coronary artery disease and chest pain.
  
  
  METHODS
  We studied endothelium-dependent (after infusion of 10(-6) M to 10(-4) M of acetylcholine) and endothelium-independent (after administration of 18 to 36 micrograms of adenosine) coronary flow reserve among patients with nonobstructive coronary artery disease and chest pain who were undergoing assessment at Mayo Clinic Rochester. Coronary blood flow was derived from coronary artery diameter assessed by quantitative angiography and Doppler flow velocities.
  
  
  RESULTS
  The cohort consisted of 203 patients (158 female and 45 male patients), who ranged in age from 17 to 78 years (mean, 51). Most patients (92%) had at least one risk factor for atherosclerosis; a substantial proportion had undergone extensive cardiac and noncardiac evaluation. Whereas 41.5% of the patients had normal coronary flow reserve, 58.5% had an abnormal response: 11.3% an impaired response to adenosine (flow velocity ratio of 2.5 or less), 29.2% an impaired response to acetylcholine (flow reserve ratio of 1.5 or less), and 18% a combined abnormality. No correlation (r2 = 0.03) was noted between endothelium-dependent and endothelium-independent flow reserve.
  
  
  CONCLUSIONS
  Most study patients with chest pain and nonobstructive coronary artery disease undergoing coronary vasomotor evaluation had risk factors for coronary artery disease and diverse abnormalities in endothelium-dependent or endothelium-independent coronary flow reserve (or both). These findings underscore the need for a comprehensive assessment.
authors.affiliation: Center for Coronary Physiology and Imaging, Mayo Clinic Rochester, Minnesota 55905, USA.
authors.forename: D
authors.initials: D
authors.lastname: Hasdai
authors.forename: D R
authors.initials: DR
authors.lastname: Holmes
authors.forename: S T
authors.initials: ST
authors.lastname: Higano
authors.forename: J C
authors.initials: JC
authors.lastname: Burnett
authors.forename: A
authors.initials: A
authors.lastname: Lerman
mesh_terms: D000109:Acetylcholine; D000241:Adenosine; D000293:Adolescent; D000328:Adult; D000368:Aged; D000787:Angina Pectoris / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology*; D001783:Blood Flow Velocity; D017023:Coronary Angiography; D003326:Coronary Circulation; D003327:Coronary Disease / Q000150:complications / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology*; D015150:Echocardiography, Doppler; D004730:Endothelium, Vascular / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007261:Infusions, Intra-Arterial; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012307:Risk Factors; D014665:Vasodilator Agents
chemical_list: D014665:Vasodilator Agents; D000241:Adenosine; D000109:Acetylcholine