Clinical outcomes after investigation for pulmonary embolism using CT angiography and venography.
BACKGROUND
The diagnosis of pulmonary embolism (PE) still requires long work-up periods and multiple tests.


OBJECTIVE
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.


METHODS
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.


RESULTS
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.


CONCLUSIONS
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%.
Instituto Cárdio Pulmonar, Salvador, BA, Brazil. esdarze@cardiopulmonar.com.br
Eduardo S
ES
Darze
João F M
JF
Braghiroli
Ricardo V
RV
Almeida
Enio P
EP
Araújo
Sergio M
SM
Toscano
César Augusto
CA
Araújo-Neto
D000328:Adult; D000368:Aged; D000792:Angiography / Q000379:methods*; D002423:Cause of Death; D002985:Clinical Protocols; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D010690:Phlebography / Q000379:methods; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging*; D013902:Radiography, Thoracic / Q000379:methods; D012307:Risk Factors; D015898:Tomography Scanners, X-Ray Computed; D014057:Tomography, X-Ray Computed / Q000379:methods*; D054556:Venous Thromboembolism / Q000000981:diagnostic imaging