The routine use of platelet function tests in elective coronary artery bypass grafting: 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. The aim was to investigate the predictive value and to justify routine preoperative use of multiple electrode aggregometry 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 (ADPHS) tests. RESULTS: ADPHS and ASPI test results significantly predicted total bleeding > 1000 ml (AUC, 0.685, p < .001; 0.695, p = .039). Sensitivity and specificity were 62.9% and 40.0%, 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: 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.

Practical Aspects of Monitoring of Antiplatelet Therapy.

Despite the application of new antiplatelet drugs (prasugrel and ticagrelor), dual antiplatelet therapy with clopidogrel and aspirin remains the standard for patients with acute coronary syndrome undergoing percutaneous coronary intervention, especially in countries of low socioeconomic status. Regardless of the proven benefits, numerous studies have shown that certain groups of patients who receive standard doses of clopidogrel and aspirin do not respond adequately, and many of them also exhibit adverse cardiovascular events. Studies have shown that the risk of stent thrombosis and ischemic complications is higher in patients with: acute coronary syndrome, diabetes mellitus, thrombocytosis, reduced systolic function of the left ventricle with ejection fraction less than 30%, presence of multiple stents, longer and thinner stents, and renal failure. In these patients it is particularly important to assess the response to clopidogrel and selecting adequate antiplatelet therapy; this provides an impetus for platelet function tests. The second especially significant group to target for laboratory evaluation includes patients with increased risk of bleeding, such as elderly patients, patients with low body weight, anemia, thrombocytopenia, renal failure, past or current ventricular or duodenal ulcer, coagulopathy, or liver disease. The third important application of platelet function tests entails the preparation and evaluation of the time for surgical interventions or invasive diagnostic procedures in patients on antiplatelet therapy. These tests can also be helpful for monitoring the effects of therapy of bleeding due to platelet dysfunction. For high-risk patients the careful selection of optimal antiplatelet drug(s) on the basis of estimated individual risk of thrombosis and bleeding, pharmacodynamic characteristics of each drug, and patient̀s comorbidity remains essential.

Application of Rotational Thromboelastometry in Patients with Acute Promyelocytic Leukemia.

INTRODUCTION: Hemorrhagic early death (HED) remains a major cause of treatment failure among patients with acute promyelocytic leukemia (APL). We aimed to investigate the prognostic potential of rotational thromboelastometry (ROTEM) for bleeding in patients with APL. MATERIALS AND METHODS: 31 newly-diagnosed APL patients (median age of 40 years; 14 female/17 male) that underwent treatment at the Clinic of Hematology UCCS from 2016-2020 with all-trans retinoic acid and anthracyclines were recruited. CBCs (complete blood count), conventional coagulation tests (CCTs), and ROTEM parameters obtained before treatment initiation were evaluated. RESULTS: All patients demonstrated at least one ROTEM parameter out of the reference range. ROTEM parameters associated with significant hemorrhage were EXTEM clotting time (CT) (P = 0.041) and INTEM amplitude 10 (A10) (P = 0.039), however, only EXTEM CT (P = 0.036) was associated with HED. Among CBCs and CCTs, only platelets were associated with significant bleeding (P = 0.015), while D-dimer was associated with both bleeding and HED (P = 0.001 and P = 0.002, respectively). CONCLUSION: Our results indicate that ROTEM parameters may reveal hypocoagulability in APL patients and have the potential to improve current hemorrhage prognostic methods. Additionally, these results suggest the combination of ROTEM and CCTs might be useful in identifying patients at risk for HED.