title: Optimal timing of clopidogrel discontinuation in Japanese patients: platelet aggregation test using the VerifyNow® system.
abstract: OBJECTIVE
  The Japanese Circulation Society recommends discontinuation of antiplatelet therapy 7-14 days before major surgery. However, reports on the relationship between the timing of clopidogrel discontinuation and the risk of postoperative bleeding in Japanese subjects are lacking. We assessed the optimal timing of clopidogrel discontinuation before elective surgery using the VerifyNow® P2Y12 assay. In addition, the relationship between preoperative platelet function and risk of postoperative bleeding was evaluated.
  
  
  METHODS
  Study 1: Between June 2012 and December 2014, Platelet function was examined by the VerifyNow P2Y12 assay in patients scheduled for cardiac surgery, every other day after clopidogrel cessation. Study 2: We compared the preoperative platelet function, measured by the VerifyNow, with the postoperative bleeding.
  
  
  RESULTS
  Study 1: Twenty-four patients were included in this study. The mean P2Y12 reaction units (PRU) on Day-0 was 186, and increased significantly to 283 PRU on Day-7 in a time-dependent manner after clopidogrel discontinuation (p = 0.001). The mean PRU value significantly exceeded the cutoff of 230 on Day-5. Study 2: Correlation between the preoperative aspirin reaction units (ARU) and postoperative bleeding showed a slight inverse correlation in patients undergoing aortic valve replacement (rS = -0.363, p = 0.013), mitral valve plasty (rS = -0.300, p = 0.085) and off-pump coronary artery bypass (rS = -0.176, p = not significant).
  
  
  CONCLUSIONS
  Platelet aggregation had already recovered at 5 days after clopidogrel cessation. Surgeons could consider decreasing the interval from clopidogrel discontinuation to surgery from the recommended 7-14 days. The VerifyNow assay can be used to predict the risk of perioperative bleeding.
authors: Department of Cardiovascular Surgery, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama, 701-0192, Japan. hirokit22@gmail.com.
authors: Hiroki
authors: H
authors: Takiuchi
authors: Department of Cardiovascular Surgery, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama, 701-0192, Japan.
authors: Kazuo
authors: K
authors: Tanemoto
mesh_terms: D000368:Aged; D001021:Aortic Valve / Q000601:surgery; D001760:Bleeding Time; D006348:Cardiac Surgical Procedures / Q000379:methods*; D000077144:Clopidogrel; D047549:Coronary Artery Bypass, Off-Pump / Q000379:methods; D017558:Elective Surgical Procedures / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008943:Mitral Valve / Q000601:surgery; D010974:Platelet Aggregation / Q000187:drug effects; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000009:adverse effects*; D010979:Platelet Function Tests / Q000379:methods; D019106:Postoperative Hemorrhage / Q000517:prevention & control*; D011300:Preoperative Care; D011446:Prospective Studies; D058921:Purinergic P2Y Receptor Antagonists / Q000378:metabolism; D013988:Ticlopidine / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives*
chemical_list: D010975:Platelet Aggregation Inhibitors; D058921:Purinergic P2Y Receptor Antagonists; D000077144:Clopidogrel; D013988:Ticlopidine
keywords: Clopidogrel cessation; Platelet function; VerifyNow assay