title: Prevalence of Coronary Microvascular Dysfunction Among Patients With Chest Pain and Nonobstructive Coronary Artery Disease.
abstract: OBJECTIVE
  This study assessed the prevalence of coronary microvascular abnormalities in patients presenting with chest pain and nonobstructive coronary artery disease (CAD).
  
  
  BACKGROUND
  Coronary microvascular abnormalities mediate ischemia and can lead to an increased risk of cardiovascular events.
  
  
  METHODS
  Using an intracoronary Doppler guidewire, endothelial-dependent microvascular function was examined by evaluating changes in coronary blood flow in response to acetylcholine, whereas endothelial-independent microvascular function was examined by evaluating changes in coronary flow velocity reserve in response to intracoronary adenosine. Patients were divided into 4 groups depending on whether they had a normal (+) or abnormal (-) coronary blood flow (CBF) in response to acetylcholine (Ach) and a normal (+) or abnormal (-) coronary flow velocity reserve (CFR) in response to adenosine (Adn): CBFAch+, CFRAdn+ (n = 520); CBFAch-, CFRAdn+ (n = 478); CBFAch+, CFRAdn- (n = 173); and CBFAch-, CFRAdn- (n = 268).
  
  
  RESULTS
  Two-thirds of all patients had some sort of microvascular dysfunction. Women were more prevalent in each group (56% to 82%). Diabetes was uncommon in all groups (7% to 12%), whereas hypertension and hyperlipidemia were relatively more prevalent in each group, although rates for most conventional cardiovascular risk factors did not differ significantly between groups. There were no significant differences in the findings of noninvasive functional testing between groups. In a multivariable analysis, age was the only variable that independently predicted abnormal microvascular function.
  
  
  CONCLUSIONS
  Patients with chest pain and nonobstructive CAD have a high prevalence of coronary microvascular abnormalities. These abnormalities correlate poorly with conventional cardiovascular risk factors and are dissociated from the findings of noninvasive functional testing.
authors.affiliation: Division of Cardiovascular Diseases, Mayo College of Medicine, Rochester, Minnesota.
authors.forename: Jaskanwal D
authors.initials: JD
authors.lastname: Sara
authors.affiliation: Division of Cardiovascular Diseases, Mayo College of Medicine, Rochester, Minnesota.
authors.forename: R Jay
authors.initials: RJ
authors.lastname: Widmer
authors.affiliation: Division of Cardiovascular Diseases, Mayo College of Medicine, Rochester, Minnesota.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Matsuzawa
authors.affiliation: Division of Biomedical Statistics and Informatics, Mayo College of Medicine, Rochester, Minnesota.
authors.forename: Ryan J
authors.initials: RJ
authors.lastname: Lennon
authors.affiliation: Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota.
authors.forename: Lilach O
authors.initials: LO
authors.lastname: Lerman
authors.affiliation: Division of Cardiovascular Diseases, Mayo College of Medicine, Rochester, Minnesota. Electronic address: lerman.amir@mayo.edu.
authors.forename: Amir
authors.initials: A
authors.lastname: Lerman
mesh_terms: D000109:Acetylcholine / Q000008:administration & dosage; D000241:Adenosine / Q000008:administration & dosage; D000328:Adult; D000367:Age Factors; D000368:Aged; D001783:Blood Flow Velocity; D016009:Chi-Square Distribution; D003324:Coronary Artery Disease / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology*; D003326:Coronary Circulation / Q000187:drug effects; D003331:Coronary Vessels / Q000187:drug effects / Q000503:physiopathology*; D015150:Echocardiography, Doppler; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008833:Microcirculation / Q000187:drug effects; D017566:Microvascular Angina / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology*; D055806:Microvessels / Q000187:drug effects / Q000503:physiopathology*; D008875:Middle Aged; D008910:Minnesota / Q000453:epidemiology; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D015995:Prevalence; D012039:Regional Blood Flow; D012307:Risk Factors; D012737:Sex Factors; D014664:Vasodilation; D014665:Vasodilator Agents / Q000008:administration & dosage
chemical_list: D014665:Vasodilator Agents; D000241:Adenosine; D000109:Acetylcholine
keywords: coronary microvascular dysfunction; endothelial dysfunction; nonobstructive coronary artery disease