In hypercoagulable disorders due to protein S or protein C deficiency, which anticoagulants are recommended?

• A. Heparin
• B. Warfarin or DOAC
• C. Aspirin
• D. No anticoagulation

Answer: (B)

In protein C or protein S deficiency, the problem is a tendency to form venous clots, so long-term systemic anticoagulation is needed rather than just antiplatelet therapy. Warfarin and direct oral anticoagulants (DOACs) are effective for ongoing prevention of recurrent thrombosis because they directly inhibit the clotting cascade (warfarin by reducing vitamin K–dependent factors; DOACs by directly inhibiting factor Xa or thrombin). Heparin is great for immediate treatment or short-term bridging but is not practical as a long-term outpatient option. Aspirin, while helpful for arterial userites, does not adequately prevent venous thrombosis. In some cases with protein C deficiency, warfarin initiation is bridged with heparin to avoid a transient hypercoagulable state, while DOACs bypass that issue.