title: Elevated platelet reactivity in stable angina pectoris without significant coronary flow obstruction.
abstract: BACKGROUND
  There are many different causes of angina pectoris without significant coronary flow obstruction in major coronary arteries. Examples include Prinzmetal angina and small vessel atherosclerotic disease.
  
  
  METHODS
  We investigated individuals with stable angina pectoris subject to elective coronary angiography. To keep the study group as homogeneous as possible, patients with diabetes mellitus were excluded. Subjects with normal coronary angiograms (n = 13) or insignificant (< 50%) coronary flow obstruction(s) (n = 4) were grouped together. The remaining cohort (n = 96) with at least one significant (> or = 50%) flow obstruction in at least one major coronary artery served as controls.
  
  
  RESULTS
  Before angiography, platelet activity in vitro on stimulation with a thrombin-receptor activating peptide (TRAP-6) (57 micromol/l and 74 micromol/l) and ADP (1.7 micromol/l and 8.5 micromol/l) was determined. Angina pectoris individuals without significant flow obstruction in major coronary arteries had enhanced platelet reactivity both when stimulated with TRAP-6 and ADP (P < 0.01 for both TRAP-6 concentrations and P < 0.05 for both ADP concentrations, respectively.
  
  
  CONCLUSIONS
  It is concluded that angina pectoris without significant flow impediment in major epicardial arteries is associated with augmented platelet reactivity.
authors.affiliation: Department of Internal Medicine, the Vrinnevi Hospital, Norrköping, Sweden. jaremo@beta.telenordia.se
authors.forename: P
authors.initials: P
authors.lastname: Järemo
authors.forename: M
authors.initials: M
authors.lastname: Milovanovic
authors.forename: Tl
authors.initials: T
authors.lastname: Lindahl
authors.forename: A
authors.initials: A
authors.lastname: Richter
mesh_terms: D000244:Adenosine Diphosphate / Q000494:pharmacology; D000328:Adult; D000368:Aged; D000787:Angina Pectoris / Q000097:blood* / Q000503:physiopathology; D001792:Blood Platelets / Q000187:drug effects* / Q000502:physiology*; D003326:Coronary Circulation; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000494:pharmacology; D015539:Platelet Activation; D018179:Receptors, Thrombin
chemical_list: D010446:Peptide Fragments; D018179:Receptors, Thrombin; C082835:thrombin receptor peptide (42-47); D000244:Adenosine Diphosphate