D-Dimer in Patients High Risk for Pulmonary Embolism

For years, we've operated under the teaching that D-dimer testing is a no-go in patients with a high pre-test probability for pulmonary embolism (PE). The rationale? The higher prevalence of PE in this group decreases the negative predictive value of the test, increasing the risk of missing the diagnosis. A recent publication in Academic Emergency Medicine is challenging this long-held belief. But before we overhaul our practice and start withholding CTPA in high-risk patients, let's take a closer look at the data.