High D‐dimer levels increase the likelihood of pulmonary embolism

. Objective. To determine the utility of high quantitative D‐dimer levels in the diagnosis of pulmonary embolism. Methods. D‐dimer testing was performed in consecutive patients with suspected pulmonary embolism. We included patients with suspected pulmonary embolism with a high risk for venous thromboembolism, i.e. hospitalized patients, patients older than 80 years, with malignancy or previous surgery. Presence of pulmonary embolism was based on a diagnostic management strategy using a clinical decision rule (CDR), D‐dimer testing and computed tomography. Results. A total of 1515 patients were included with an overall pulmonary embolism prevalence of 21%. The pulmonary embolism prevalence was strongly associated with the height of the D‐dimer level, and increased fourfold with D‐dimer levels greater than 4000 ng mL−1 compared to levels between 500 and 1000 ng mL−1. Patients with D‐dimer levels higher than 2000 ng mL−1 and an unlikely CDR had a pulmonary embolism prevalence of 36%. This prevalence is comparable to the pulmonary embolism likely CDR group. When D‐dimer levels were above 4000 ng mL−1, the observed pulmonary embolism prevalence was very high, independent of CDR score. Conclusion. Strongly elevated D‐dimer levels substantially increase the likelihood of pulmonary embolism. Whether this should translate into more intensive diagnostic and therapeutic measures in patients with high D‐dimer levels irrespective of CDR remains to be studied.