Search

The article offers information that global coagulation assays (GCA) have been proposed as better surrogate measures of the haemostatic profile compared to traditional coagulation studies. It mentions that traditional coagulation assays such as prothrombin time (PT) and activated partial thromboplastin time (APTT) measure the time to the start of clot formation.

Introduction: Some patients with thrombocytopenia may be at risk of bleeding although quantitative platelet count is not always a sufficient predictive factor. Global coagulation assays such as thromboelastography (TEG®), calibrated automated thrombogram (CAT) and overall haemostatic potential (OHP) may provide a better assessment of an individual's haemostatic profile. Methods: Blood samples were collected from thrombocytopenic patients. TEG® was performed on citrated whole blood, while CAT and OHP were performed on platelet‐poor plasma. Results were compared to our previously collected normal controls. Results: Fifty‐eight participants (24 immune thrombocytopenia, 34 chemotherapy/malignancy‐related) with mean age of 57.5 years were recruited. Compared to normal controls, thrombocytopenic participants had comparable maximum amplitude but reduced clot lysis (0.0% vs 0.6%; P < 0.001) on TEG® with reduced endogenous thrombin potential on CAT (1252.2 vs 1353.0 nmol/L/min; P = 0.040). No differences were seen in the OHP parameters. TEG® showed significant difference between marked and mild thrombocytopenia groups with minimal differences seen on CAT and OHP. Those with marked thrombocytopenia showed reduced maximum amplitude (47.2 vs 57.8 mm; P = 0.002) as expected while participants with mild thrombocytopenia (platelet count 100‐150 × 109/L) paradoxically demonstrated increased maximum amplitude (66.4 vs 57.8 mm; P < 0.001). Conclusion: Global coagulation assays, particularly TEG®, can detect subtle differences in coagulation in thrombocytopenic patients. While patients with marked thrombocytopenia showed reduced maximum amplitude, patients with mild thrombocytopenia appear to paradoxically show increased maximum amplitude, suggesting compensatory activity within the coagulation pathway which may in part explain why not all thrombocytopenic patients have bleeding complications. [ABSTRACT FROM AUTHOR]

• Patients with plasma cell dyscrasia showed hypercoagulable thromboelastography. • Peak thrombin was increased in patients with plasma cell dyscrasia. • Patients with subsequent arterial thrombosis demonstrated hypofibrinolysis. • There were no significant differences seen between patients with myeloma and MGUS. • Global coagulation assays provide better coagulation assessment in these patients. [ABSTRACT FROM AUTHOR]

Normal haemostasis requires maintenance of a careful equilibrium between the necessity to clot when bleeding and the retention of fluid phase at all other times. Disruption of this equilibrium can result in catastrophic outcomes, e.g. acute myocardial infarction and pulmonary embolism. However, despite the significant therapeutic advances in cardiovascular medicine over recent years, our ability to provide an accurate cardiovascular risk assessment remains an unmet need. Routine coagulation testing is not a useful reflection of haemostasis and cannot be reliably used to predict bleeding and thrombosis risks. Global coagulation assays such as viscoelastic testing, thrombin and fibrin generation have been proposed as better measures of the haemostatic function. These assays, particularly viscoelastic testing, have been increasingly used to assess bleeding risks and guide blood product replacement in trauma and massive transfusion settings. However, the role of these assays in thrombosis is less well-defined but given the complexities of the coagulation system, these global coagulation assays when used in combination may provide a better assessment of cardiovascular and thrombosis risk at an individual level. Hence, we explore the role of some of the currently available global coagulation assays – the viscoelastic, thrombin generation and fibrin generation tests – and provide a review of the literature of the current evidence for these assays specifically in the field of venous thromboembolism and cardiovascular diseases. • There is no biomarker currently available to quantify thrombotic risk. • Data regarding use of global coagulation assays in thrombosis is emerging. • Further studies evaluating clinical outcomes using these assays are required. [ABSTRACT FROM AUTHOR]