What is the approach to evaluating a patient for hypercoagulability (Hypercoagulable state)?

From the Guidelines

A hypercoagulable workup is essential for patients presenting with acute limb ischemia, particularly those with atypical presentations, and should include prothrombin time, partial thromboplastin time, platelet count, and levels of factor V Leiden, factor II (prothrombin) C-20210a, anti-cardiolipin antibody, protein C, protein S, and anti-thrombin III 1. When evaluating a patient for hypercoagulability, it is crucial to consider the clinical context and presentation.

• The initial evaluation should include a complete blood count, comprehensive metabolic panel, and coagulation studies (PT/INR, PTT) 1.
• Specific tests for inherited thrombophilias include Factor V Leiden mutation, Prothrombin G20210A mutation, Protein C and S deficiency, Antithrombin deficiency, and hyperhomocysteinemia.
• For acquired thrombophilias, testing for antiphospholipid antibodies (lupus anticoagulant, anticardiolipin antibodies, and beta-2 glycoprotein I antibodies), JAK2 mutation, and paroxysmal nocturnal hemoglobinuria should be considered. The timing of these tests is critical, and they should be performed either before starting anticoagulation or at least 2-4 weeks after discontinuing therapy to avoid false results 1.
• Acute phase reactants like Protein C, Protein S, and antithrombin can be falsely low during acute thrombosis or while on certain anticoagulants. The results of this workup may influence treatment duration, with some thrombophilias warranting extended or indefinite anticoagulation 1.
• Genetic counseling should be considered for patients with inherited thrombophilias, especially if family planning is relevant, as these conditions can have implications for relatives and pregnancy management.

From the Research

Hypercoagulable Workup

• A hypercoagulable workup is a series of tests used to diagnose conditions that increase the risk of blood clots [ 2 ].
• The workup typically includes a combination of laboratory tests, such as complete blood cell count, platelet count, prothrombin time, and activated partial thromboplastin time [ 3 ].
• Other tests that may be included in a hypercoagulable workup are:
  • Thrombelastography [ 4 ]
  • Endogenous thrombin potential [ 5 ]
  • Prothrombin fragment F1+2 [ 5 ]
  • D-dimer [ 5, 6 ]
  • Platelet count [ 3, 6 ]
• The results of these tests can help identify underlying conditions that may be contributing to hypercoagulability, such as:
  • Factor V Leiden [ 2 ]
  • Prothrombin G20210A [ 2 ]
  • Deficiencies of protein C, protein S, or antithrombin [ 2 ]
  • Antiphospholipid antibodies [ 2 ]
• The diagnosis and treatment of hypercoagulable conditions can be complex and may require consultation with a specialist [ 2 ].

Laboratory Evaluation

• Laboratory tests are used to evaluate hypercoagulability and diagnose underlying conditions [ 2 ].
• The choice of tests will depend on the individual's medical history, symptoms, and risk factors [ 3 ].
• Some laboratory tests, such as thrombelastography, may be used to evaluate the effectiveness of treatment [ 4 ].

Clinical Evaluation

• A clinical evaluation is an important part of a hypercoagulable workup [ 6 ].
• The evaluation should include a thorough medical history, physical examination, and review of laboratory test results [ 3 ].
• The clinical evaluation can help identify underlying conditions that may be contributing to hypercoagulability and guide treatment decisions [ 2 ].