Increasing the D-dimer threshold for patients with low clinical pretest probability effectively rules out PE (PEGeD)

Référence

Kearon C, de Wit K, Parpia S, et al, for the PEGeD Study Investigators. Diagnosis of pulmonary embolism with d-dimer adjusted to clinical probability. N Engl J Med 2019;318(22):2125-34.

Sommaire

C-PTP in conjunction with D-dimer testing can be a useful strategy for ruling out PE. Currently, patients with low C-PTP and a D-dimer value of less than 500 ng/mL are considered to be ruled out for PE. This study investigates whether a higher D-dimer cutoff value of less than 1000 ng/mL in patients with low C-PTP and the usual cutoff value of less than 500 ng/mL in patients with moderate C-PTP can also effectively rule out PE. The investigators enrolled 2056 patients primarily from emergency departments and outpatient clinics who had symptoms or signs suggestive of PE. The Wells Clinical Prediction Rule was applied to determine a patient's pretest probability of PE. Using the PEGeD strategy, patients with a low C-PTP and a D-dimer level of less than 1000 ng/mL or those with a moderate C-PTP and D-dimer level of less than 500 ng/mL did not undergo further diagnostic testing for PE, and did not receive anticoagulant therapy. All other patients underwent either CT pulmonary angiography or ventilation-perfusion lung scanning, and received anticoagulant therapy if a PE was discovered. Patients were assessed at 90 days via telephone or a clinic visit for evidence of venous thromboembolism (VTE). After excluding 39 enrolled patients who did not meet eligibility criteria, 2017 patients were analyzed: Their mean age was 52 years, two-thirds were women, 86.9% had a low C-PTP, 10.8% had a moderate C-PTP, and 2.3% had a high C-PTP. Of the 1325 patients with a low or moderate C-PTP and a negative D-dimer test result, including the subset of 315 patients with low C-PTP and a D-dimer level of 500 ng/mL to 999 ng/mL, none had VTE at 90-day follow-up. Additionally, none of the 40 patients who had a moderate C-PTP and D-dimer level of less than 500 ng/mL had evidence of VTE at follow-up. Increasing the D-dimer threshold to less than 1000 ng/mL for ruling out PE in patients with a low C-PTP decreased the need for chest imaging from 51.9% to 34.3%. Further, D-dimer testing increased from 86.9% to 97.7% by allowing for testing patients with a moderate C-PTP.