There are a few oddities specific to the YEARS protocol precluding universal recommendation as is. Most important, D-dimer results were routinely available prior to risk stratification. This meant clinicians had access to the D-dimer result when assessing the patient as “PE is most likely diagnosis.” It is naive to expect foreknowledge of the D-dimer result did not influence their risk stratification, introducing potentially detrimental effects on internal validity and certainly on generalizability.
Explore This IssueACEP Now: Vol 36 – No 08 – August 2017
At the least, these prospective results, along with the retrospective and observational series, support revisiting our thresholds for D-dimer. In patients for whom PE is not likely, it is probably reasonable practice to consider D-dimer results below 1,000 ng/mL as properly further decreasing the likelihood of PE. Overtesting and overdiagnosis of PE have long been recognized as problematic, and applying even this simplest additional layer of Bayesian reasoning to testing for PE will help our patients by decreasing the costs and harms from testing without a disproportionate increase in harms from missed PE.
- Righini M, Van Es J, Den Exter PL, et al. Age-adjusted D-dimer cutoff levels to rule out pulmonary embolism: the ADJUST-PE study. JAMA. 2014;311(11):1117-1124.
- Kohn MA, Klok FA, van Es N. D-dimer interval likelihood ratios for pulmonary embolism. Acad Emerg Med. 2017;24(7):832-837.
- Barritt DW, Jordan SC. Anticoagulant drugs in the treatment of pulmonary embolism. A controlled trial. Lancet. 1960;1(7138):1309-1312.
- Kline JA, Hogg MM, Courtney DM, et al. D-dimer threshold increase with pretest probability unlikely for pulmonary embolism to decrease unnecessary computerized tomographic pulmonary angiography. J Thromb Haemost. 2012;10(4):572-581.
- Char S, Yoon HC. Improving appropriate use of pulmonary computed tomography angiography by increasing the serum D-dimer threshold and assessing clinical probability. Perm J. 2014;18(4):10-15.
- van der Hulle T, Cheung WY, Kooij S, et al. Simplified diagnostic management of suspected pulmonary embolism (the YEARS study): a prospective, multicentre, cohort study [published online ahead of print May 23, 2017]. Lancet.
- van der Hulle T, den Exter PL, Erkens PG, et al. Variable D-dimer thresholds for diagnosis of clinically suspected acute pulmonary embolism. J Thromb Haemost. 2013;11(11):1986-1992.
- van Es J, Beenen LF, Douma RA, et al. A simple decision rule including D-dimer to reduce the need for computed tomography scanning in patients with suspected pulmonary embolism. J Thromb Haemost. 2015;13(8):1428-1435.