For a hemodynamically stable patient with suspected DVT or PE, what is the initial diagnostic approach and treatment plan?

• A. Immediate anticoagulation without imaging
• B. D-dimer only; no imaging
• C. Use pretest probability with D-dimer in low probability; CT pulmonary angiography for suspected PE; start therapeutic anticoagulation (LMWH or DOAC) unless contraindicated; consider compression stockings and IVC filter if needed
• D. Start warfarin only

Answer: (C)

The main idea is to use risk-based testing and treat with anticoagulation when safe. In a hemodynamically stable patient with suspected DVT or PE, you first assess pretest probability. If the probability is low, a D-dimer test helps rule out clotting; a negative D-dimer effectively excludes PE (and often DVT) without imaging. If the probability is high or the D-dimer is positive, you move to imaging to confirm the diagnosis, with CT pulmonary angiography as the preferred test for suspected PE. For suspected DVT, duplex ultrasonography of the legs is typically used.

Treatment should be started with therapeutic anticoagulation (a form such as low-molecular-weight heparin or a DOAC) unless there is a contraindication (e.g., active bleeding). If anticoagulation cannot be given, an IVC filter may be considered to reduce PE risk. As adjuncts, compression stockings can be used to alleviate symptoms and may help reduce post-thrombotic syndrome, though they are not a substitute for anticoagulation or definitive imaging.