Platelet function assay to determine the optimal preoperative cessation period of aspirin

ABSTRACT

BACKGROUND: This study was conducted to assess preoperative residual antiplatelet-induced platelet dysfunction using a platelet function assay to determine the optimal cessation period of aspirin during the preoperative period. METHODS: Patients older than 20 years, who were scheduled for elective surgery under general anesthesia, were enrolled prospectively. The last ingestion of the aspirin had occurred within the previous 10 days before surgery (aspirin 100 mg per day). No history of antiplatelet intake was documented in the control group. Platelet function was assessed using a platelet function analyzer-100 (PFA-100). Receiver operating characteristic (ROC) curves were plotted to determine the ability of aspirin cessation time in order to predict platelet function as assessed by the PFA. Patients were assigned to groups according to the period of aspirin discontinuation. RESULTS: Two hundred patients were enrolled in this study (100 control group and 100 aspirin group). The mean PFA value of the control group was significantly lower than that of the treated groups. The areas under the ROC curve (0.65, P = 0.03) of aspirin cessation period to discriminate PFA prolongation were significant. There were significant decreases in PFA values when aspirin medication was discontinued for 7 days, but not when the intake was discontinued for 5 days. CONCLUSIONS: Platelet function recovered if aspirin intake was discontinued > 7 days prior to surgery; therefore, in these patients, a preoperative platelet function test is not essential. However, the residual antiplatelet effect of aspirin should be assessed using the PFA in patients who discontinue aspirin less than 7 days prior to surgery.