Platelet activity measured by a rapid turnaround assay identifies coronary artery bypass grafting patients at increased risk for bleeding and transfusion complications after clopidogrel administration

J Thorac Cardiovasc Surg. 2013 Nov;146(5):1259-1266, 1266.e1; discussion 1266. doi: 10.1016/j.jtcvs.2013.06.029. Epub 2013 Aug 13.


Background: We sought to establish a metric for easily estimating bleeding and transfusion risks for cardiac surgery patients after antiplatelet agent use.

Methods: Deidentified records of patients who underwent coronary artery bypass grafting (CABG) at our institution (January 2010-June 2011) were searched for patients without identified risk factors for excessive bleeding who underwent documented P2Y12 testing after clopidogrel administration (n = 276). Clinical outcomes were analyzed according to whether preoperative platelet function was higher (platelet reactivity units [PRUs], ≥237) or lower (PRU, <237) and according to preoperative PRU cutoffs: high (>290, or no clopidogrel), intermediate (200-290), or low (<200).

Results: Eighty-five patients (57%) received allogeneic blood products at 24 hours or less postoperatively: 33 (22%) received fresh frozen plasma, and 57 (38%) received platelets. The median 12-hour chest tube output (CTO) was 350 mL (interquartile range, 260-490 mL); CTO was "high" (>437 mL) in 62 (42%) of the clopidogrel-treated patients. Lower-PRU patients were more likely to receive coagulation factors (odds ratio [OR], 2.82; P = .0004) and to have high CTO or coagulation factor transfusion (OR, 2.35; P = .02) than higher-PRU patients. Likewise, intermediate- and low-PRU patients had incrementally greater incidences of high CTO (OR, 1.72; P = .002) and coagulation factor transfusion (OR, 2.08; P < .0001) than high-PRU/no clopidogrel patients. High CTO or coagulation factor transfusion was more frequent in intermediate-PRU (OR, 2.67; P = .02) and low-PRU (OR, 5.08; P = .0002) patients than in high-PRU/no clopidogrel patients.

Conclusions: Among clopidogrel-treated CABG patients, preoperative platelet function testing can identify those at increased risk for postoperative bleeding and transfusion.

Keywords: 13; 23.1; 24; 54; ACCF; AHA; American College of Cardiology Foundation; American Heart Association; BSA; CABG; CI; CTO; IQR; OR; PCI; PRU; QA; SBU; SQDUG; SQIP; STS; Society of Thoracic Surgeons; Stony Brook University; Surgical Quality Data Users Group; Surgical Quality Improvement Program; body surface area; chest tube output; confidence interval; coronary artery bypass grafting; interquartile range; odds ratio; percutaneous coronary intervention; platelet reactivity units; quality assurance.

MeSH terms

  • Aged
  • Blood Platelets / drug effects*
  • Blood Platelets / metabolism
  • Chi-Square Distribution
  • Clopidogrel
  • Coronary Artery Bypass / adverse effects*
  • Decision Support Techniques*
  • Female
  • Humans
  • Logistic Models
  • Male
  • Middle Aged
  • Multivariate Analysis
  • Odds Ratio
  • Patient Selection
  • Platelet Aggregation Inhibitors / adverse effects*
  • Platelet Function Tests*
  • Postoperative Hemorrhage / blood
  • Postoperative Hemorrhage / chemically induced*
  • Postoperative Hemorrhage / therapy*
  • Predictive Value of Tests
  • Preoperative Care
  • Purinergic P2Y Receptor Antagonists / adverse effects*
  • Receptors, Purinergic P2Y12 / blood
  • Receptors, Purinergic P2Y12 / drug effects
  • Retrospective Studies
  • Risk Assessment
  • Risk Factors
  • Ticlopidine / adverse effects
  • Ticlopidine / analogs & derivatives*
  • Time Factors
  • Transfusion Reaction*
  • Treatment Outcome


  • P2RY12 protein, human
  • Platelet Aggregation Inhibitors
  • Purinergic P2Y Receptor Antagonists
  • Receptors, Purinergic P2Y12
  • Clopidogrel
  • Ticlopidine