title: Use of an objective tool to assess platelet inhibition prior to off-pump coronary surgery to reduce blood usage.
abstract: BACKGROUND
  The current standard of care is to delay coronary surgery 5-7 days after clopidogrel exposure to prevent bleeding complications. We sought to determine the utility of an objective tool (ie, the VerifyNow assay) to measure platelet inhibition (PI) in patients receiving preoperative clopidogrel prior to off-pump coronary artery bypass grafting surgery (OPCABG).
  
  
  METHODS
  Between June 2007 and July 2009, a total of 482 isolated OPCABG procedures were performed at our institution. In 160 patients, the VerifyNow assay results were used to determine timing of the OPCABG. These patients were compared to the remaining 322 patients. We divided the cohort into 4 subgroups: Group 1 patients (n = 205) were not taking clopidogrel; Group 2 patients (n = 117) were taking clopidogrel, but the test was not performed; Group 3 patients (n = 122) were taking clopidogrel and had a preoperative PI result of ≤20%; and Group 4 patients (n = 38) had ≥21% preoperative PI.
  
  
  RESULTS
  Demographic and clinical factors were compared in all groups. The median waiting time for surgery from the last dose of clopidogrel was 6 days for the control groups and 3 days for the groups where the test was performed (P<.001). Reoperation for bleeding occurred most often in Group 4 (7.9%; P=.003). Blood utilization was lower in Group 1 (24.4%) than in Groups 2 (34.2%), 3 (40.2%), or 4 (55.3%) (P<.001). Major complications and postoperative length of stay were similar in all groups.
  
  
  CONCLUSIONS
  Utilization of a PI tool in the preoperative assessment of OPCABG patients exposed to clopidogrel can provide valuable information to guide the timing of coronary surgery and may lead to a decrease in reoperation for bleeding and blood usage.
authors.affiliation: The Valley Heart and Vascular Institute, 223 North van Dien Avenue, Ridgewood, NJ 07450, USA. mbrizzio@gmail.com
authors.forename: Mariano E
authors.initials: ME
authors.lastname: Brizzio
authors.forename: Richard E
authors.initials: RE
authors.lastname: Shaw
authors.forename: Beth
authors.initials: B
authors.lastname: Bosticco
authors.forename: Mary
authors.initials: M
authors.lastname: Collins
authors.forename: Juan B
authors.initials: JB
authors.lastname: Grau
authors.forename: Andrew W C
authors.initials: AW
authors.lastname: Mak
authors.forename: Alex
authors.initials: A
authors.lastname: Zapolanski
mesh_terms: D000244:Adenosine Diphosphate / Q000494:pharmacology; D000368:Aged; D001780:Blood Coagulation Tests; D016063:Blood Loss, Surgical / Q000517:prevention & control*; D001803:Blood Transfusion; D000077144:Clopidogrel; D047549:Coronary Artery Bypass, Off-Pump; D005260:Female; D006801:Humans; D008297:Male; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage*; D011183:Postoperative Complications; D011300:Preoperative Care; D012086:Reoperation; D013988:Ticlopidine / Q000008:administration & dosage / Q000031:analogs & derivatives*
chemical_list: D010975:Platelet Aggregation Inhibitors; D000244:Adenosine Diphosphate; D000077144:Clopidogrel; D013988:Ticlopidine