PB0131 - Impedance aggregometry in elective coronary surgery : a prospective observational trial

Background: Preoperative use of platelet function tests contributes to the decrease of
re‐intervention rate due to bleeding and the necessity of transfusion in coronary artery
bypass grafting (CABG) patients

Aims: The aim was to investigate the predictive value and to justify routine preoperative use of impedance aggregometry (multiplate electrode test) in these patients.

Methods: A prospective observational trial which included 416 consecutive patients subjected to elective isolated CABG was conducted. The Multiplate® test was used to assess platelet function. Platelet function test results, postoperative blood loss, and transfusion requirements were compared between high and low bleeding risk patients. Receiver operating characteristic analysis was performed to assess the sensitivity and specificity of the arachidonic acid (ASPI) and adenosine di‐phosphate high sensitive (ADP HS) test.

Results: ADPHS and ASPI test results significantly predicted total bleeding > 1000ml (AUC, 0.685, p < .001; 0.695, p = .039). Sensitivity and specificity were 62.9% and40.0%, for ADPHS ≤602, and 70.8% and 41.8%, for ASPI ≤ 453. The sensitivity and specificity of cut‐off values recommended by the manufacturer were 84.2% and 40.0% for ADPHS ≤ 500, while for ASPI < 600 the values were 54.7% and 62.2%. More platelets and cryoprecipitate were transfused in patients with ADPHS ≤ 602.5 (p < .001; p = .035). Patients with ADPHS ≤ 500 had a higher rate of red blood count, platelet and cryoprecipitate transfusion (p <.001p <.001; p = .013). The manufacturer's ASPI test cut‐off values showed no statistically significant prediction for a higher transfusion rate.

Conclusion(s): Preoperative platelet function tests should be conducted systematically for all elective CABG patients who were on dual antiplatelet therapy after adjusting test cut‐off values for each population.