Evaluation of Feasible Timing of Elective Noncardiac Procedure After Antiplatelet Discontinuation in Patients Treated With Antiplatelet Agents

Background The current standard of care is to delay noncardiac procedure (NCP) 5 to 7 days after discontinuation of antiplatelet agents (APAs) in patients with coronary stents. However, it is often difficult to follow because of concerns over stent thrombosis. The point-of-care aspirin/P2Y 12 assay (VerifyNow; Accumetrics Inc, San Diego, CA) is useful to evaluate platelet reactivity in conjunction with APAs. In this study, we evaluated the feasible timing after discontinuation of APAs. Methods and Results Sixty-two patients taking APAs, who were scheduled to undergo elective NCP, were enrolled. All patients took either aspirin 100 mg or aspirin 100 mg plus clopidogrel 75 mg daily. The aspirin-reactivity unit (ARU) and P2Y 12 -reactivity unit (PRU) were measured from 0 days (day 0, no discontinuation) to as long as 5 days (day 5, 5 days after discontinuation) depending on each procedure schedule. For 15 patients, baseline ARU and PRU (592 and 288) before aspirin/clopidogrel loading at index percutaneous coronary intervention were collected as control. For ARU after discontinuation of APA, days 0 to 5 values progressively increased over time (489.4 ± 85.3, 512.6 ± 77.0, 589.9 ± 58.8, 613.6 ± 47.3, 632.6 ± 49.2, 662.0 ± 4.2). Likewise, for PRUs, days 0 to 5 values also increased over time (245.0 ± 96.9, 253.9 ± 80.9, 270.9 ± 45.8, 289.0 ± 68.6, 306.5 ± 29.2, 351.0 ± 8.5). The ARU and PRU well correlated with days after APA discontinuation by linear regression analysis ( y = 490.897 + 39.238 * x , R 2 = 0.43, P y = 241.739 + 16.701 * x , R 2 = 0.092, P = 0.018, respectively). Assuming baseline ARU and PRU as 592 and 288, the mean days after complete reversal of platelet reactivity by APAs are 2.6 and 2.8, respectively. Conclusions The feasible timing of NCP after discontinuation of APAs showed less than 5 days. VerifyNow is useful in the evaluation of antiplatelet reversal after discontinuation of APAs.