Pulmonary embolism · Ruling out pulmonary embolism
Diagnosis of Pulmonary Embolism with d-Dimer Adjusted to Clinical Probability
| Design | Prospective management study |
|---|---|
| Treatment | D-dimer threshold adjusted to clinical pretest probability: <1000 ng/mL if low, <500 ng/mL if moderate |
| Control | Conventional fixed 500 ng/mL threshold |
| Population | 2017 patients with suspected pulmonary embolism, 7.4% of whom had PE on initial testing |
| Follow-up | 3 months |
| Primary endpoint | Venous thromboembolism during 3-month follow-up in patients in whom PE was ruled out without imaging |
| Result | Of 1325 patients with a low clinical pretest probability and D-dimer below 1000 ng/mL, or moderate probability and D-dimer below 500 ng/mL, none had venous thromboembolism during follow-up. |
| Secondary endpoints | Proportion of patients avoiding CT pulmonary angiography |
A combination of a low C-PTP and a d-dimer level of less than 1000 ng per milliliter identified a group of patients at low risk for pulmonary embolism during follow-up.
The trial authors, in the published abstract
One of three concordant strategies — with YEARS and ADJUST-PE — that all do the same thing: raise the D-dimer threshold when clinical probability is low, and scan fewer people. Which algorithm a department adopts matters less than adopting one.
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 Nov 28;381(22):2125-2134.