title: Inverse relationships between coronary blood flow obstruction and platelet reactivity in stable angina pectoris.
abstract: This study investigates relationships between platelet reactivity and coronary blood flow obstruction in stable angina pectoris. Consented were 36 patients with single-vessel disease. The subjects were divided into two groups. One group (n=14) had less severe (<=80%) and the second group (n=22) had severe coronary flow impairment (90%). Before elective coronary angiography platelet in vitro reactivity in venous whole blood was determined using a flow cytometry technique. A thrombin-receptor activating peptide (TRAP-6) (0.77 and 0.06 g/l) and ADP (8.5 and 1.7 micromol/l) were used to activate platelets. The number of fibrinogen positive cells (%) i.e., activated platelets after stimulation was employed as experimental parameter. Less severe flow obstruction was associated with more reactive platelets. When stimulating with 0.77 g/l TRAP-6 the number of activated platelets was 64+/-15 (SD)%. The corresponding value for the group with severe flow obstruction was 40+/-17(SD)%. The difference is significant (P<0.001). 0.06 g/l TRAP-6 yielded similar results (P<0.01). Also when using 8.5 micromol/l ADP to challenge platelets less severe flow obstruction was associated with enhanced reactivity (P<0.01). 1.7 micromol/l ADP generated comparable results (P<0.05). Thus, in stable angina pectoris coronary flow obstruction is inversely related to platelet reactivity.
authors: Department of Internal Medicine, The Vrinnevi Hospital, Norrköping, Sweden.
authors: M
authors: M
authors: Milovanovic
authors: S G
authors: SG
authors: Fransson
authors: A
authors: A
authors: Richter
authors: P
authors: P
authors: Järemo
mesh_terms: D000244:Adenosine Diphosphate / Q000494:pharmacology; D000368:Aged; D000787:Angina Pectoris / Q000097:blood* / Q000175:diagnosis; D003326:Coronary Circulation; D003327:Coronary Disease / Q000097:blood* / Q000175:diagnosis; D005260:Female; D005340:Fibrinogen / Q000032:analysis; D005434:Flow Cytometry; D006801:Humans; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000494:pharmacology; D015539:Platelet Activation
chemical_list: D010446:Peptide Fragments; C082835:thrombin receptor peptide (42-47); D000244:Adenosine Diphosphate; D005340:Fibrinogen