A 26-year-old man undergoes follow-up evaluation after hospitalization for deep venous thrombosis last week. He reports no recent travel, surgery, or immobilization. He has a sister who was diagnosed with an unprovoked deep venous thrombosis 1 year ago at 35 years of age. Medical history is otherwise unremarkable. His only medication is rivaroxaban. On physical examination, vital signs are normal. The examination is otherwise unremarkable. The possibility of an inherited thrombophilia is discussed with the patient. After reviewing the risks and benefits of additional testing, he would like to be further evaluated for a possible thrombophilia.

Which of the following is the ideal testing strategy?

A. Test now
B. Test in 2 months
C. Test a saved blood sample obtained during hospitalization but before anticoagulation
D. Temporarily stop rivaroxaban in 1 year and test 2 weeks later

The ideal testing strategy is to test a saved blood sample obtained during hospitalization before starting anticoagulation. Therefore, the correct option is C.

Explanation:

The ideal testing strategy for the 26-year-old man with a family history of unprovoked deep venous thrombosis (DVT) is to test a saved blood sample obtained during hospitalization but before anticoagulation. Testing for thrombophilia is not recommended immediately after anticoagulation has been started, as it can lead to false negative results.

By testing a saved blood sample obtained before anticoagulation, the patient can be evaluated for inherited thrombophilia without the interference of anticoagulation medication.

Therefore, the correct option is C.