Pretreatment with oral anticoagulants decreases platelet activation in patients before and after percutaneous coronary intervention.
BACKGROUND
Platelet activation plays a major role in acute vessel closure after coronary angioplasty. In the randomized Balloon Angioplasty and Anticoagulation Study (BAAS), pretreatment with oral anticoagulants in addition to aspirin resulted in a 47% reduction of acute complications as compared with aspirin alone. This result may suggest a direct effect of oral anticoagulants on platelet activation.


RESULTS
Patients were randomized to aspirin alone (group A, n = 26) or to aspirin plus oral anticoagulants started one week before angioplasty (group B, n = 26). Platelet response tests were performed 1 hour before (baseline) and 1 hour after intervention and on day 1. Platelet activation was measured by flow cytometry, as the number of antibody-positive platelets per 10,000 counted. Platelet function was evaluated with use of the PFA-100 analyzer. In group B, the median number of P-selectin-positive platelets was lower before (28 vs. 54, P = 0.018) and after (13 vs. 24, P = 0.377) angioplasty than in group A. Also the median decrease in the number of P-selectin-positive platelets during angioplasty was lower in group B (delta = 4) than in group A (delta = 30, P = 0.022). No further significant change was observed in platelet activation on day 1 in the two groups. The ability of platelets to become stimulated as measured with the PFA-100 analyzer was not affected by oral anticoagulants.


CONCLUSIONS
Pretreatment with oral anticoagulants resulted in less activated platelets before and after coronary angioplasty, which is in agreement with its clinical effect of reducing procedural complications. Platelet function was not affected by oral anticoagulants.
ten Berg
Jurriën M
JM
Department of Cardiology, St Antonius Hospital, Nieuwegein, The Netherlands. jurtenberg@wxs.nl
Gerritsen
Wim B M
WB
Haas
Fred J L M
FJ
Kelder
Johannes C
JC
Verheugt
Freek W A
FW
Thijs Plokker
H W
HW
D000284:Administration, Oral; D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D000925:Anticoagulants / Q000008:administration & dosage*; D000990:Antithrombin III / Q000378:metabolism; D001241:Aspirin / Q000008:administration & dosage; D005260:Female; D006801:Humans; D019934:International Normalized Ratio; D008297:Male; D008875:Middle Aged; D010447:Peptide Hydrolases / Q000378:metabolism; D015539:Platelet Activation / Q000187:drug effects*; D010974:Platelet Aggregation / Q000187:drug effects
D000925:Anticoagulants; C046193:antithrombin III-protease complex; D000990:Antithrombin III; D010447:Peptide Hydrolases; D001241:Aspirin