Pneumatic tube system transport does not alter platelet function in optical and whole blood aggregometry, prothrombin time, activated partial thromboplastin time, platelet count and fibrinogen in patients on anti-platelet drug therapy

Introduction: The aim of this study was to assess pneumatic tube system (PTS) alteration on platelet function by the light transmission aggregometry (LTA) and whole blood aggregometry (WBA) method, and on the results of platelet count, prothrombin time (PT), activated partial thromboplastin time (APTT), and fibrinogen. Materials and methods: Venous blood was collected into six 4.5 mL VACUETTE® 9NC coagulation sodium citrate 3.8% tubes (Greiner Bio-One International GmbH, Kremsmünster, Austria) from 49 intensive care unit (ICU) patients on dual anti-platelet therapy and immediately hand carried to the central laboratory. Blood samples were divided into 2 Groups: Group 1 samples (N = 49) underwent PTS (4 m/s) transport from the central laboratory to the distant laboratory and back to the central laboratory, whereas Group 2 samples (N = 49) were excluded from PTS forces. In both groups, LTA and WBA stimulated with collagen, adenosine-5’-diphosphate (ADP), arachidonic acid (AA) and thrombin-receptor-activated-peptide 6 (TRAP-6) as well as platelet count, PT, APTT, and fibrinogen were performed. Results: No statistically significant differences were observed between blood samples with (Group 1) and without (Group 2) PTS transport (P values from 0.064 – 0.968). The AA-induced LTA (bias: 68.57%) exceeded the bias acceptance limit of ? 25%. Conclusions: Blood sample transportation with computer controlled PTS in our hospital had no statistically significant effects on platelet aggregation determined in patients with anti-platelet therapy. Although AA induced LTA showed a significant bias, the diagnostic accuracy was not influenced

The role of viscoelastic testing in assessing peri-interventional platelet function and coagulation

We carried out a literature search in MEDLINE (PubMed) and EMBASE literature databases to provide a concise review of the role of viscoelastic testing in assessing peri-interventional platelet function and coagulation. The search identified 130 articles that were relevant for the review, covering the basic science of VHA and VHA in clinical settings including cardiac surgery, cardiology, neurology, trauma, non-cardiac surgery, obstetrics, liver disease, and COVID-19. Evidence from these articles is used to describe the important role of VHAs and platelet function testing in various peri-interventional setups. VHAs can help us to comprehensively assess the contribution of platelets and coagulation dynamics to clotting at the site-of-care much faster than standard laboratory measures. In addition to standard coagulation tests, VHAs are beneficial in reducing allogeneic transfusion requirements and bleeding, in predicting ischemic events, and improving outcomes in several peri-interventional care settings. Further focused studies are needed to confirm their utility in the peri-interventional case

Impact of preoperative use of P2Y12 receptor inhibitors on clinical outcomes in cardiac and non-cardiac surgery: A systematic review and meta-analysis.

OBJECTIVE: To review systematically the evidence and perform a meta-analysis of benefits and risks associated with use of P2Y12 receptor inhibitors in coronary artery bypass graft-, non-cardiac- and device surgery. DATA SELECTION AND ANALYSIS: We performed a meta-analysis of published studies. Patients with preoperative use of clopidogrel, ticagrelor or prasugrel (late discontinuation: <5 days before surgery or no discontinuation) were compared with patients without preoperative use of the respective drug (early discontinuation: 5 days before surgery or no users of P2Y12 receptor inhibitors). Outcomes evaluated were re-operation for major bleeding, death, myocardial infarction, combined major adverse cardiac events (MACEs) and major haematoma. Using a random effect model, relative risks (RRs) and 95% confidence intervals (CI) were calculated for each outcome. RESULTS: Fifty-four studies met the selection criteria and included 50,048 patients. Preoperative use of clopidogrel on top of aspirin in patients undergoing coronary artery bypass graft was associated with a 2.5-fold increased risk of re-operation for bleeding (95% CI: 1.92-3.25; p<0.001) and a 1.47-fold increased risk of death (95% CI: 1.25-1.72; p<0.001), but did not diminish the risk for myocardial infarction (RR: 0.96; 95% CI: 0.75-1.25; p=0.18) or MACE (RR: 1.16; 95% CI: 0.90--1.50; p=0.30). In patients undergoing non-cardiac surgery, preoperative use of clopidogrel increased the RR of re-operation for major bleeding by 2.05-fold (95% CI: 1.13-3.73; p=0.002) but did not reduce the RR for MACE or death. Clopidogrel use during cardiac device implantation raised the RR for procedure-related haematoma by 3.0-fold (95% CI: 1.30--6.94; p=0.001). Whereas preoperative ticagrelor use did not increase the risk for mortality (RR: 1.03; 95% CI: 0.49-2.14), preoperative prasugrel use tended to increase the risk for death (RR: 5.06; 95% CI: 0.54-47.65). CONCLUSION: Preoperative exposure to clopidogrel on top of aspirin did not reduce the risk of MACE but was associated with increased risk of bleeding and mortality

Impact of preoperative use of P2Y12 receptor inhibitors on clinical outcomes in cardiac and non-cardiac surgery: A systematic review and meta-analysis

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Consensus and update on the definition of on-treatment platelet reactivity to adenosine diphosphate associated with ischemia and bleeding

Dual antiplatelet therapy with aspirin and a P2Y12 receptor blocker is a key strategy to reduce platelet reactivity and to prevent thrombotic events in patients treated with percutaneous coronary intervention. In an earlier consensus document, we proposed cutoff values for high on-treatment platelet reactivity to adenosine diphosphate (ADP) associated with post-percutaneous coronary intervention ischemic events for various platelet function tests (PFTs). Updated American and European practice guidelines have issued a Class IIb recommendation for PFT to facilitate the choice of P2Y12 receptor inhibitor in selected high-risk patients treated with percutaneous coronary intervention, although routine testing is not recommended (Class III). Accumulated data from large studies underscore the importance of high on-treatment platelet reactivity to ADP as a prognostic risk factor. Recent prospective randomized trials of PFT did not demonstrate clinical benefit, thus questioning whether treatment modification based on the results of current PFT platforms can actually influence outcomes. However, there are major limitations associated with these randomized trials. In addition, recent data suggest that low on-treatment platelet reactivity to ADP is associated with a higher risk of bleeding. Therefore, a therapeutic window concept has been proposed for P2Y12 inhibitor therapy. In this updated consensus document, we review the available evidence addressing the relation of platelet reactivity to thrombotic and bleeding events. In addition, we propose cutoff values for high and low on-treatment platelet reactivity to ADP that might be used in future investigations of personalized antiplatelet therapy