Prevalence of Pulmonary Embolism in Patients with DVT on Doppler
Approximately 70% of patients with confirmed pulmonary embolism have a residual deep vein thrombosis detectable on venography, though only 30-50% will have DVT detected on compression ultrasound/Doppler. 1
The Inverse Relationship: DVT Found in PE Patients
The question asks about PE prevalence in DVT patients, but the strongest guideline evidence addresses the inverse—how often DVT is found when PE is already confirmed:
- When venography is systematically performed in patients with angiographically confirmed PE, residual DVT is found in 70% of cases 1
- Autopsy studies establish that PE arises from lower limb DVT in 90% of patients 1, 2
- Modern compression ultrasound (Doppler) detects DVT in only 30-50% of patients with confirmed PE 1
The discrepancy between venography (70%) and ultrasound (30-50%) detection rates reflects the technical limitations of ultrasound in detecting calf vein thrombi and cases where the thrombus has completely embolized. 1
Limited Direct Evidence: PE Prevalence in DVT Patients
When the question is reversed—looking at PE prevalence in patients presenting with proximal DVT—one high-quality study found 56% had PE at baseline when systematically evaluated with lung scanning and/or pulmonary angiography. 3
Key Study Details:
- Among 350 patients with phlebography-proven proximal DVT who underwent systematic PE evaluation, 197 (56%) had concurrent PE 3
- The majority of these patients with PE had no pulmonary symptoms (sensitivity of symptoms for PE was only 74%, specificity 67%) 3
- This represents the most direct answer to your question from high-quality prospective data 3
Clinical Implications and Diagnostic Strategy
Finding a proximal DVT on compression ultrasound in a patient with suspected PE is considered sufficient to warrant anticoagulant treatment without further PE-specific testing. 1
Important Caveats:
- Patients with PE confirmed indirectly by DVT detection should still undergo risk assessment for PE severity and early death risk 1
- The majority of PE patients have no clinical symptoms or signs of DVT, despite the high pathophysiologic association 1, 2
- Compression ultrasound has high specificity (96%) but low sensitivity (41%) for detecting DVT in the setting of suspected PE 1
Diagnostic Performance:
- In one study comparing Doppler ultrasound to venography in PE patients, ultrasound had 76% sensitivity and 100% specificity for DVT detection 4
- Venography remains the gold standard but is rarely performed in modern practice 4
Summary of the Evidence Hierarchy
The most direct answer comes from research data showing 56% of patients with confirmed proximal DVT have concurrent PE when systematically evaluated 3, though most are asymptomatic. The inverse relationship (70% of PE patients have DVT on venography) is more extensively documented in guidelines 1, 2 but represents the opposite direction of your question.