Regular Article Preoperative platelet aggregation predicts perioperative blood loss and rethoracotomy for bleeding in patients receiving dual antiplatelet treatment prior to coronary surgery Dariusz Plicner a , Piotr Mazur a,b, ⁎, Hubert Hymczak a , Jarosław Stoliński a , Radosław Litwinowicz a,b , Rafał Drwiła a,b , Anetta Undas a,b a John Paul II Hospital, Krakow, Poland b Institute of Cardiology, Jagiellonian University Medical College, Krakow, Poland abstract article info Article history: Received 21 February 2015 Received in revised form 13 April 2015 Accepted 28 April 2015 Available online xxxx Keywords: Coronary artery bypass grafting CABG Bleeding Transfusions Clopidogrel Platelet aggregation Introduction: Patients scheduled for coronary artery bypass graft surgery (CABG) are commonly treated with clopidogrel. We sought to assess the relation between preoperative platelet aggregation and bleeds in CABG pa- tients on clopidogrel. Material and methods: In a case-control study, we compared 52 consecutive patients undergoing isolated CABG on aspirin and clopidogrel 75 mg/d versus 50 controls on aspirin monotherapy. Platelet aggregation induced by 10 μmol/l adenosine di-phosphate (ADP) in platelet-rich plasma was measured in subjects on clopidogrel within 5 days prior to surgery. ADP-induced aggregation of ≥50% was used to define subjects with satisfactory inhibition of platelet reactivity. Results: In 29 patients with preoperative ADP-induced aggregation ≥50%, compared with 23 subjects with aggre- gation b 50%, lower chest-tube drainage volumes (after 6 h, p = 0.002; and 12 h, p = 0.001) and fewer rethoracotomies were observed (p = 0.03). The former group was characterized with lower transfusion rates of packed red blood cells (p = 0.009), platelet concentrate (p = 0.04) and fresh frozen plasma (p = 0.001). Pa- tients with ADP-induced aggregation ≥50% did not differ from untreated controls regarding the postoperative drainage, transfusions and rethoracotomy. The incidence of thromboembolic events and death during perioper- ative period were similar in all groups. Multivariate logistic regression identified ADP-induced aggregation b 50% as the only independent predictor of rethoracotomy (OR = 2.94 [1.12-7.75], p = 0.029). Conclusions: Patients on aspirin and clopidogrel b 5 days before CABG who had preoperative ADP-induced platelet aggregation ≥50% have bleeding risk similar to those receiving aspirin monotherapy. Reduced platelet reactivity to ADP can predict postoperative bleeding in CABG patients on dual antiplatelet therapy. © 2015 Elsevier Ltd. All rights reserved. Introduction Dual antiplatelet therapy (DAPT) involving aspirin and clopidogrel is common among patients who require coronary artery by-pass grafting (CABG). The benefits and safety of preoperative clopidogrel use before CABG have been extensively investigated. Two clinical trials (Clopidogrel in Unstable angina to prevent Recurrent ischemic Events [CURE] and Acute Catheterization and Urgent Intervention Triage strategy [ACUITY]) demonstrated a cardiovascular events risk reduction and increased major bleeding risk among urgent CABG patients operated on clopidogrel [1,2]. Interestingly, only the patients who received clopidogrel ≤ 5 days from CABG had increased risk of both major bleeding and ischemic events [1,2]. Berger et al. reported increased risk of bleeding- related complications in DAPT patients undergoing CABG when the last dose of clopidogrel was taken ≤ 4 days before surgery [3]. Re- cently, Miceli and colleagues demonstrated in 926 CABG patients that DAPT with clopidogrel continued until the surgery is associated with elevated risk of myocardial infarction (MI) and bleeding compliations [4]. Similar results were presented by Firanescu et al. in a randomized trial [5], however platelet reactivity was not assessed in any of these studies. Several methods of platelet function testing are available, including point-of-care tests like VerifyNow, Multiplate, or Plateletworks. Thrombosis Research xxx (2015) xxx–xxx Abbreviations: ADP, adenosine di-phosphate; APTT, activated partial thromboplastin time; BMI, body mass index; CABG, Coronary artery bypass grafting; CK-MB, creatine kinase MB fraction; CPB, cardiopulmonary bypass; DAPT, dual antiplatelet therapy; FFP, fresh fro- zen plasma; Hb, hemoglobin; HPA, high platelet aggregation; INR, international normalized ratio; LPA, low platelet aggregation; LTA, light transmission aggregometry; MI, myocardial infarction; PCI, percutaneous coronary intervention; PMI, perioperative myocardial infarc- tion; PRBC, packed red blood cells; STS, Society of Thoracic Surgeons. ⁎ Corresponding author at: Institute of Cardiology Jagiellonian University Medical College, 80 Pradnicka St., 31-202 Krakow, Poland. Tel.: +48 12 6143075; fax: +48 12 4233900. E-mail address: piotr.k.mazur@gmail.com (P. Mazur). TR-05946; No of Pages 7 http://dx.doi.org/10.1016/j.thromres.2015.04.037 0049-3848/© 2015 Elsevier Ltd. All rights reserved. Contents lists available at ScienceDirect Thrombosis Research journal homepage: www.elsevier.com/locate/thromres Please cite this article as: Plicner D, et al, Preoperative platelet aggregation predicts perioperative blood loss and rethoracotomy for bleeding in patients receiving dual anti..., Thromb Res (2015), http://dx.doi.org/10.1016/j.thromres.2015.04.037