Reaktywność płytek krwi we wczesnym okresie po pomostowaniu tętnic wieńcowych bez użycia krążenia pozaustrojowego u pacjentów stosujących małą dawkę kwasu acetylosalicylowego

Abstract

Introduction. Acetylsalicylic acid (ASA) is the antiplatelet drug most used in the perioperative period in patients undergoing coronary artery bypass grafting (CABG). Off-pump coronary artery bypass grafting (OPCAB) is likely to alter platelet (PLT) function to a lesser extent than CABG with the use of cardiopulmonary bypass and may potentially result in high on-aspirin platelet reactivity (HAPR) in the postoperative period. Materials and methods. The aim of this prospective study was to characterise serum thromboxane B2 (TXB 2 ) variability and ASA-dependent platelet reactivity in patients with stable coronary artery disease undergoing OPCAB treated with a single daily dose of 75 mg of ASA. Blood sampling was performed 2 hours and 24 hours after ASA intake on the day before surgery, and on the 2 nd and 7 th days after the operation. Results. A PLT counts reduction and a mean platelet volume increase were observed on the 2 nd day after OPCAB. A PLT counts increase was found on the 7 th postoperative day. A significant increase (p = 0.03) in the percentage of patients with insufficient laboratory ASA efficacy (defined by serum TXB 2 ≥ 7.2 ng/mL) was observed on the 7 th postoperative day compared to preoperative values (52% vs 20% respectively, p = 0.02). A significant increase in median platelet reactivity and in the percentage of patients with HAPR (defined by VerifyNow ® Aspirin test result ≥ 550 ARU) was observed on the 7 th postoperative day in comparison with the values before OPCAB (48% vs 12%, p = 0.007). Conclusions. In the group of patients taking a standard daily dose of 75 mg of ASA, a substantial number of patients failed to attain optimal inhibition of serum TXB 2 or had HAPR before surgery and on the 7 th day after OPCAB. A significant decrease in serum TXB 2 levels on the 2nd day after OPCAB did not correlate with PLT reactivity. The optimal dose of ASA is of interest for further studies of efficacy and clinical outcomes after OPCAB.