From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
For a patient with known deep vein thrombosis (DVT) presenting to the emergency room from radiology, I recommend obtaining a complete blood count (CBC), comprehensive metabolic panel (CMP), coagulation studies (PT/INR, PTT), and D-dimer, with consideration of the timing of anticoagulation therapy administration, as rivaroxaban may reduce the sensitivity of D-dimer testing 1. The CBC helps assess for anemia or infection, while the CMP evaluates kidney and liver function which is crucial for anticoagulant therapy decisions. Coagulation studies establish baseline clotting parameters before initiating or adjusting anticoagulation. Although the patient already has a confirmed DVT, a D-dimer may help assess clot burden. Some key points to consider:
- The effect of rivaroxaban on D-dimer levels, as it may decrease the sensitivity of the test 1
- The importance of clinical decision rules, such as Wells score, in combination with D-dimer to assess the need for objective imaging to rule out DVT 2
- The potential for D-dimer as a stand-alone test to rule out proximal DVT, with a failure rate of 0.6% (95% CI 0.1%-1.8%) 3
- The complementary use of impedance plethysmography (IPG) with D-dimer testing to improve diagnostic accuracy 4 If the patient is on anticoagulation therapy, specific tests may be needed - factor Xa levels for patients on rivaroxaban, apixaban, or edoxaban; INR for warfarin users; or anti-Xa activity for those on low molecular weight heparin. Additionally, consider troponin and BNP if pulmonary embolism is suspected, as DVT can lead to this potentially life-threatening complication. It is essential to prioritize the single most recent and highest quality study, which in this case is 1, to guide management decisions and minimize the risk of morbidity, mortality, and impact on quality of life.