Kearon C, de Wit K, Parpia S, et al. Diagnosis of pulmonary embolism with D-dimer adjusted to clinical probability. N Engl J Med. 2019;381(22):2125-2134.
This prospective study utilized D-dimer levels and clinical pretest probability (using the Wells criteria for pulmonary embolism) to determine the cutoffs and combinations that would identify the highest number of patients in whom pulmonary embolism (PE) could be ruled out, thus minimizing the chest imaging performed and the number of patients started on anticoagulant therapy. The study found that patients with a low clinical probability and a D-dimer <1000 ng/mL (standard level is <500 ng/mL) were at low risk for PE. Chest imaging was reduced when a D-dimer <1000 ng/mL was utilized versus the standard level of <500 ng/mL.