Thromb Haemostasis
-
Randomized Controlled Trial Comparative Study Clinical Trial
Biological efficacy of low against medium dose aspirin regimen after coronary surgery: analysis of platelet function.
The failure of aspirin to inhibit platelet function has been documented in patients undergoing coronary artery bypass graft (CABG) surgery, but the causes of "aspirin-resistance" remain uncertain. The aim of this study was to investigate the efficacy of aspirin in patients undergoing CABG surgery receiving either 100 mg or 325 mg of oral aspirin for 5-days. Platelet function was tested the day before surgery and on day +1 and day +5, and evaluated by changes in collagen-induced thromboxane-A2 (TxA2) release and platelet aggregation following stimulation with collagen, ADP and epinephrine. ⋯ Western blot analysis provided no evidence for the presence of COX-2 in platelets, while the up-regulation of p38-MAPK following platelet-stimulation and surgery was seen. The inhibition of COX-2 (NS398) or p38-MAPK (SB203580) activity did not affect platelet aggregation and TxA2-release on day +5. In summary, there was no evidence for inherent or acquired aspirin-resistance in this surgical population, or for the involvement of either COX-2 or p38-MAPK.