Key Points
- To prospectively determine whether serial noninvasive leg testing for proximal-vein thrombosis safely eliminates the need for pulmonary angiography in patients with nondiagnostic ventilation-perfusion lung scans.
- Prospective comparative study of 1564 consecutive patients presenting with suspected pulmonary embolism.
- Patients underwent ventilation-perfusion lung scanning alongside objective testing for proximal-vein thrombosis.
- Anticoagulant therapy was withheld in patients with nondiagnostic scans and negative serial leg testing, followed by long-term clinical monitoring.
- Among 627 patients with nondiagnostic lung scans and negative serial noninvasive leg tests who received no anticoagulants, venous thromboembolism occurred in 12 patients (1.9%; 95% CI, 0.8% to 3.0%).
- Venous thromboembolism occurred in 4 of 586 patients (0.7%; 95% CI, 0.02% to 1.3%) with normal scans not receiving anticoagulants, and in 8 of 145 patients (5.5%; 95% CI, 1.8% to 9.2%) with high-probability scans receiving anticoagulants.
Structured PICO
Does serial noninvasive leg testing safely rule out venous thromboembolism in patients with suspected pulmonary embolism and nondiagnostic lung scans?
PPopulation1564 consecutive patients with suspected pulmonary embolism who underwent ventilation-perfusion lung scanning and objective testing for proximal-vein thrombosis
IInterventionSerial noninvasive leg testing for proximal-vein thrombosis with withholding of anticoagulant therapy if negative
CComparatorPatients with normal lung scans (anticoagulant withheld) and high probability lung scans (received anticoagulant therapy)
OOutcomeVenous thromboembolism on long-term follow-uphard clinical
Serial noninvasive leg testing is a safe alternative to pulmonary angiography for ruling out venous thromboembolism in patients with suspected pulmonary embolism and nondiagnostic lung scans.