Clinical outcomes after investigation for pulmonary embolism using CT angiography and venography

• Published in: Arquivos brasileiros de cardiologia Vol. 99; no. 2; pp. 740 - 746
• Main Authors: Darze, Eduardo S, Braghiroli, João F M, Almeida, Ricardo V, Araújo, Enio P, Toscano, Sergio M, Araújo-Neto, César Augusto
• Format: Journal Article
• Language: English
• Published: Brazil 01-08-2012
• Subjects: Adult; Aged; Angiography - methods; Cause of Death; Clinical Protocols; Cohort Studies; Female; Humans; Lung - diagnostic imaging; Male; Middle Aged; Outcome Assessment (Health Care); Phlebography - methods; Pulmonary Embolism - diagnostic imaging; Radiography, Thoracic - methods; Risk Factors; Tomography Scanners, X-Ray Computed; Tomography, X-Ray Computed - methods; Venous Thromboembolism - diagnostic imaging
• DOI: 10.1590/S0066-782X2012005000058
• EISSN: 1678-4170

The diagnosis of pulmonary embolism (PE) still requires long work-up periods and multiple tests.
We aim to assess clinical outcomes after a negative investigation using a combined protocol of CT pulmonary angiography and CT venography (CTA/CTV) as a sole diagnostic test in unselected patients with suspected PE.
This retrospective cohort study enrolled consecutive patients with suspected PE who were investigated with a combined CTA/CTV protocol. Patients who had an initially negative investigation and were not anticoagulated were followed for 6 months for the occurrence of recurrent venous thromboembolic events.
Out of 425 patients with suspected PE, 62 (14.6%) had venous thromboembolism diagnosed on the initial CTA/CTV. The mean age was 56 ± 19 years and 61% of the population fell into the low clinical probability category. Isolated deep vein thrombosis represented 21% of all venous thromboembolic events, and when considering the whole population, CTV was associated with an increment in diagnostic yield of 3.1%. Our cohort was composed of 320 patients with initially negative CTA/CTVs and who were not anticoagulated. After 6 months of follow up, only three patients presented with recurrent thromboembolic events (0.9%; 95% CI -0.1% - 2.0%) and none was fatal. There were no PE-related deaths.
Our study suggests that a diagnostic strategy that utilizes CTA/CTV as a sole diagnostic test can safely rule out PE in a low to moderate risk population and is associated with favorable outcomes with a negative predictive value of 99.1%.