title: Typical chest pain and normal coronary angiogram: cardiac risk factor analysis versus PET for detection of microvascular disease.
abstract: Angiography of patients with typical chest pain reveals normal epicardial coronary arteries in about 20%. Coronary flow reserve (CFR) determination is an elaborate, but helpful, task, as only the evidence of microvascular disease enables appropriate therapy. We prospectively evaluated the incidence of a dysfunctional microcirculation and searched for predictive parameters of a reduced CFR.
  
  
  METHODS
  In 79 consecutive patients (52 females, 27 males) with typical angina and a normal angiogram and 10 control subjects (6 females, 4 males), CFR was measured by 13N-ammonia rest/dipyridamole PET and correlated with clinical parameters individually and summarized as the number of risk factors (NRF) using an elaborated cardiac risk factor score.
  
  
  RESULTS
  Sixty-five percent of patients had a reduced CFR (CFR < 2.5). CFR correlated with NRF (r = 0.55, P < 0.001), systolic blood pressure (r = 0.46, P < 0.001), interventricular septal thickness (r = 0.33, P < 0.01), and age (r = 0.25, P = 0.02). Eighty-five percent of patients with a high risk factor score (NRF > or = 5) had a reduced CFR. In contrast, 100% of our patients with a low risk factor score (NRF < 2) presented a normal CFR. In total, 55% of our patients could be allocated to either one of these groups.
  
  
  CONCLUSIONS
  In about two thirds of patients, anginal pain can be explained by a reduced CFR. Risk factors have a cumulative negative effect on CFR. A clinical cardiac risk factor analysis enables estimation of individual probability of microvascular dysfunction in a significant proportion of these patients. However, CFR measurements are recommended for those with an intermediate NRF.
authors.affiliation: Department of Cardiology, Medical University of Vienna, Vienna, Austria. senta.graf@meduniwien.ac.at
authors.forename: Senta
authors.initials: S
authors.lastname: Graf
authors.forename: Aliasghar
authors.initials: A
authors.lastname: Khorsand
authors.forename: Marianne
authors.initials: M
authors.lastname: Gwechenberger
authors.forename: Clemens
authors.initials: C
authors.lastname: Novotny
authors.forename: Kurt
authors.initials: K
authors.lastname: Kletter
authors.forename: Heinz
authors.initials: H
authors.lastname: Sochor
authors.forename: Christian
authors.initials: C
authors.lastname: Pirich
authors.forename: Gerald
authors.initials: G
authors.lastname: Maurer
authors.forename: Gerold
authors.initials: G
authors.lastname: Porenta
authors.forename: Manfred
authors.initials: M
authors.lastname: Zehetgruber
mesh_terms: D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000502:physiology; D002637:Chest Pain / Q000175:diagnosis*; D017023:Coronary Angiography; D003326:Coronary Circulation; D004452:Echocardiography; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008055:Lipids / Q000097:blood; D008297:Male; D017566:Microvascular Angina / Q000175:diagnosis* / Q000000981:diagnostic imaging*; D008875:Middle Aged; D049268:Positron-Emission Tomography; D012372:ROC Curve; D012307:Risk Factors
chemical_list: D008055:Lipids