The Bottom Line: The data are consistent with the possibility that there may be a significant number of high pretest probability patients who have PE with negative D-dimer testing. Further study is warranted to determine whether these findings can be safely incorporated into practice.
Summary: ELISA (enzyme-linked immunosorbent assay) D-dimer testing is commonly used in the evaluation of possible pulmonary embolism (PE) in the emergency department, but is not recommended in high pretest probability patients. Whether a negative ELISA D-dimer can safely rule out PE in these patients is not known, as there have been no large studies comparing ELISA D-dimer results and outcomes in high pretest probability patients. This was a prospective observational pilot study of emergency department patients evaluated for PE. Patients evaluated for PE had pretest probability assessed by the Wells PE Score. High pretest probability was defined as: dichotomized Wells Score > 4 points and patients with trichotomized Wells Score > 6 points.