Multiple daily doses of acetyl-salicylic acid (ASA) overcome reduced platelet response to once-daily ASA after coronary artery bypass graft surgery: a pilot randomized controlled trial

作者：Paikin J S^*; Hirsh J; Gin**erg J S; Weitz J I; Chan N C; Whitlock R P; Pare G; Johnston M; Eikelboom J W

来源：Journal of Thrombosis and Haemostasis, 2015, 13(3): 448-456.

DOI：10.1111/jth.12832

• aspirin
• coronary artery bypass
• drug resistance
• perioperative period
• platelet function tests

BackgroundThe efficacy of ASA for prevention of graft failure following CABG surgery may be limited by incomplete platelet inhibition due to increased post-operative platelet turnover.
ObjectivesTo determine whether acetyl-salicylic acid (ASA) 325mg once-daily or 81mg four-times daily overcomes the impaired response to ASA 81mg once-daily in post-operative coronary artery bypass graft (CABG) patients.
MethodsWe randomized 110 patients undergoing CABG surgery to either ASA 81mg once-daily, 81mg four times daily or 325mg once-daily and compared their effects on serum thromboxane B-2 (TXB2) suppression and arachidonate-induced platelet aggregation.
ResultsOne hundred patients were included in the final analysis. Platelet counts fell after surgery, reached a nadir on day 2, and then gradually increased. Although there was near complete suppression of TXB2 on the second or third post-operative day, TXB2 levels increased in parallel with the rise in platelet count on subsequent days. This increase was most marked in patients receiving ASA 81mg once-daily and less evident in those receiving ASA four times daily. On post-operative day 4, (i) median TXB2 levels were lower with four times daily ASA than with either ASA 81mg once-daily (1.1ng/mL; Quartile(Q) Q1,Q3: 0.5, 2.4 and 13.3ng/mL; Q1,Q3: 7.8, 30.8ng/mL, respectively; P<0.0001) or ASA 325mg once-daily (3.4ng/mL; Q1,Q3: 2.0, 8.2ng/mL; P=0.002), and (ii) ASA given four times daily was more effective than ASA 81mg once-daily and 325mg once-daily at suppressing platelet aggregation.
ConclusionsFour times daily ASA is more effective than ASA 81 and 325mg once-daily at suppressing serum TXB2 formation and platelet aggregation immediately following CABG surgery.

• 出版日期2015-3