From the Guidelines
To evaluate a hypercoagulable state, the most recent and highest quality evidence recommends standard coagulation tests including prothrombin time, partial thromboplastin time, and fibrinogen levels 1. When assessing a patient for a hypercoagulable state, it is crucial to consider the timing of laboratory tests, as acute thrombosis or anticoagulation therapy can affect the results.
- Key laboratory tests for hypercoagulability include: + Prothrombin time (PT) + Activated partial thromboplastin time (aPTT) + Complete blood count (CBC) + Fibrinogen levels + D-dimer
- Additional tests may be considered based on the patient's specific risk factors and clinical presentation, such as: + Factor V Leiden mutation + Prothrombin gene mutation (G20210A) + Protein C and protein S activity + Antithrombin III levels + Lupus anticoagulant + Anticardiolipin antibodies + Beta-2 glycoprotein antibodies + Homocysteine levels + JAK2 V617F mutation testing These tests help identify inherited or acquired conditions that increase clotting risk, allowing for appropriate prophylaxis or treatment to prevent potentially life-threatening thrombotic events, thus prioritizing morbidity, mortality, and quality of life as outcomes. The most recent guideline from 2022 1 provides the highest quality evidence for the standard coagulation tests, while other studies, such as those from 2011 2 and 2015 3, offer additional recommendations but are less recent and therefore secondary in consideration.
From the Research
Laboratory Tests for Hypercoagulable State
The following laboratory tests are indicated for a hypercoagulable state:
- Prothrombin time (PT) 4
- Activated partial thromboplastin time (APTT) 4
- Bleeding time (BT) 4
- Fibrinogen and fibrinogen/fibrin degradation products 5
- Thrombocytosis 5
- Markers of coagulation activation, such as FPA, F1+2, TAT, and D-Dimer 5
- Tests for inhibitors of coagulation, such as protein C and protein S 6
- Tests for hereditary and acquired hypercoagulable conditions, such as factor V Leiden and antithrombin deficiency 6
Algorithmic Approach to Laboratory Testing
An algorithmic approach to hypercoagulability testing can help tailor assay selection to the clinical scenario, reducing unnecessary tests and potential false results 7. This approach involves guiding appropriate testing and synthesizing interpretation of results, with input from laboratory professionals.
Clinical Evaluation
A thorough patient history and complete physical examination are essential in assessing patients for potential predisposing factors for a hypercoagulable state 8. The clinical evaluation should guide the laboratory testing, and identification of a specific hypercoagulable state is crucial for prognosis and therapeutic management 8.