Risk factors determine need for CTA for PE

Risk factor assessments can rule out the need for CT angiography for pulmonary embolism, according to a new study published in Radiology.

CT angiograms were negative for pulmonary embolism (PE) in 90.2% of 2003 patients, according to researchers at the University of California, Irvine. Among the 197 patients positive for PE, 97.5% had one or more risk factors. The risk factors were age, gender, cancer, history of immbolization, excess estrogen rate, a history of venous thromboembolism, and disorders that cause blood to clot easily.

All risk factors except gender were considered statistically significant. Age of 65 years or older and immobilization were the most common risk factors in positive PE patients. Risk factor assessment had a sensitivity of 97.5% and a negative predictive value of 99% in all patients.

Of the patients negative for PE, 28.8% had no risk factors. Excluding age and gender brought that figure to 62%.

Results were published online June 15 (Epub ahead of print).