Table 2 Diagnostic criteria for VTE

Symptomatic VTE

• All patients must have diagnostic imaging performed of both legs and the lungs in order to determine baseline presence or absence of DVT or PE.

• Standard objective imaging is required to diagnose recurrent VTE. If there are symptoms from the leg(s) AND lungs, objective imaging is required for both sites.

• Diagnostic imaging results for DVT:

• Diagnostic imaging results for recurrent DVT:

 - A non-compressible venous segment of the proximal deep veins in the legs, including iliac, femoral and popliteal veins.

 - A non-compressible venous segment of the deep veins (proximal and/or distal) in the legs that had normal compression at baseline.

 - An intraluminal filling defect on venography, CT scan or MR venography of the proximal deep veins in the leg.

 - A new or extension of 5 cm or greater of intraluminal filling defect on venography, CT scan or MR venography of the deep veins in the leg, including inferior vena cava.

• Diagnostic imaging results for PE:

 - An extension of non-visualisation of the deep veins of the leg in the presence of a sudden cut-off on venography, CT scan or MR venography.

 - An intraluminal filling defect on CT pulmonary angiography.

• Diagnostic imaging results for recurrent PE:

 - A perfusion defect of at least 75% of a segment with a local normal ventilation result (mismatch defect) on ventilation-perfusion lung scintigraphy (high-probability scan).

 - A new or extension of an existing intraluminal filling defect on CT pulmonary angiography.

 - A non-high, non-diagnostic ventilation-perfusion lung scan with confirmed DVT.

 - A new sudden cut-off of vessels more than 2.5 mm in diameter on CT pulmonary angiography.

 - A new perfusion defect of at least 75% of a segment with a local normal ventilation result (mismatch defect) on ventilation-perfusion lung scintigraphy (high-probability scan).

 - A non-high, non-diagnostic ventilation-perfusion lung scan with confirmed DVT.

• Diagnostic criteria for fatal PE:

 - Objective testing as above associated with death.

 - Autopsy finding of PE contributing to death.

 - Sudden and unexplained death within the 6-month study period which cannot be attributed to a documented cause and for which PE is the most probable cause.

Incidental VTE

• Not valid as an inclusion criterion.

• Incidental PE or DVT are defined as thrombi that were reported during imaging testing performed for reasons other than for suspected PE or DVT.

• Diagnosis of incidental VTE during the required baseline imaging represents the baseline status.

• The same diagnostic imaging criteria for recurrent DVT or PE apply to confirming the presence of an incidental DVT or PE.

• Incidental DVT is only included as an outcome if located in the popliteal or more proximal leg veins.

• Incidental PE is only included as an outcome if located in segmental or more proximal pulmonary arteries.

• In patients with incidental PE involving subsegmental pulmonary arteries only, a compression ultrasound showing a new DVT is necessary to confirm a recurrent thrombotic event.