From the Guidelines
A hypercoagulability workup should be considered for patients with unprovoked venous thromboembolism (VTE), thrombosis at unusual sites, recurrent thrombosis, or family history of thrombosis, and should include tests such as complete blood count, prothrombin time, activated partial thromboplastin time, and a comprehensive metabolic panel, as well as specific tests for inherited thrombophilias and acquired thrombophilias, as recommended by the most recent guidelines 1.
When evaluating a patient for hypercoagulability, it is essential to consider the following:
- The initial evaluation should include complete blood count, prothrombin time, activated partial thromboplastin time, and a comprehensive metabolic panel.
- Specific tests for inherited thrombophilias include Factor V Leiden mutation, prothrombin G20210A mutation, protein C and S deficiency, antithrombin deficiency, and homocysteine levels.
- For acquired thrombophilias, test for antiphospholipid antibodies (lupus anticoagulant, anticardiolipin antibodies, and beta-2 glycoprotein I antibodies).
- Testing should ideally be performed at least 2-3 months after the thrombotic event and after completion of anticoagulation therapy to avoid false results.
- Acute phase reactants and anticoagulants can affect protein C, protein S, and antithrombin levels.
- Genetic testing for Factor V Leiden and prothrombin mutations can be done at any time as they are not affected by anticoagulation.
The results of this workup may influence treatment decisions, including the duration of anticoagulation therapy. For patients with identified thrombophilias, especially those with recurrent events, indefinite anticoagulation with warfarin (target INR 2-3) or direct oral anticoagulants may be recommended, as suggested by recent studies 1. Family screening may be appropriate for first-degree relatives of patients with inherited thrombophilias.
It is crucial to prioritize the most recent and highest quality study, which in this case is the 2021 guideline for the prevention of stroke in patients with stroke and transient ischemic attack 1, when making decisions about hypercoagulability workup and treatment.
From the Research
Hypercoagulability Workup
- Hypercoagulable states are characterized by laboratory abnormalities or clinical conditions that increase the risk of thrombosis 2
- These states can be primary (inherited) or secondary (acquired), with primary states including antithrombin III deficiency, protein C and protein S deficiency, and abnormalities of the fibrinolytic system 2
- Secondary hypercoagulable states are associated with underlying systemic diseases or clinical conditions, such as malignancy, pregnancy, and myeloproliferative disorders 2
Laboratory Evaluation
- Laboratory testing for hypercoagulability includes evaluation of activated protein C resistance, factor V Leiden, prothrombin G20210A, and deficiencies of protein C, protein S, or antithrombin 3
- Testing should be tailored to the clinical scenario, using an algorithmic approach to reduce unnecessary tests and prevent false results 4
- Laboratory tests should be interpreted in the context of the patient's clinical history and physical findings 5
Clinical Assessment
- Clinical assessment of hypercoagulability involves evaluating the patient's history, physical findings, and laboratory results 5
- Risk factors for hypercoagulability include obesity, recent surgery, pregnancy, and cancer 5
- Treatment of hypercoagulable states typically involves anticoagulation therapy, such as heparin and warfarin 5
Diagnosis and Screening
- Diagnosis of coagulation disorders involves clinical assessment, laboratory testing, and evaluation of the patient's history and physical findings 6
- Screening tests for coagulation disorders include complete blood cell count, platelet count, prothrombin time, and activated partial thromboplastin time 6
- Specific laboratory tests, such as assays for factor VIII and von Willebrand factor, may be necessary to diagnose specific coagulation disorders 6