Performance of age-adjusted D-dimer cut-off to rule out pulmonary embolism.
J Thromb Haemost. 2012 May 8;
Authors: Penaloza A, Roy PM, Kline J, Verschuren F, Le Gal G, Quentin-Georget S, Delvau N, Thys F
Background:?Age-adjusted D-dimer cut-off has recently been proposed to increase D-dimer usefulness in older patients suspected of pulmonary embolism (PE). Objective:?We externally validated this age-adjusted D-dimer cut-off using different D-dimer assays in a multicenter sample of emergency department patients. Methods:?Secondary analysis of 3 prospectively collected databases (2 European, 1 American) of PE suspected patients. D-dimer performance for ruling out PE was assessed by calculating negative likelihood ratio (nLR) for D-dimer with age-adjusted D-dimer cut-off (< age x 10 in patients over 50 years) and with conventional cut-off (< 500?g/dl). Test efficiency was assessed by the number needed to test (NNT) to rule out PE in one patient. Results:?Among 4,537 patients included, overall PE prevalence was 9.9%. In overall population, nLR was 0.06 [95% CI: 0.03-0.09] with conventional cut-off and 0.08 [0.06 -0.13] with age-adjusted cut-off. Using age-adjusted cut-off, nLR was 0.09, 0.09 and 0.06 for Vidas®, Liatest® and MDA® assays respectively. Use of age-adjusted cut-off produced favorable effect on NNT in the elderly, the greatest decrease was observed in patients > 75 years: NTT halved from 8.1 to 3.6. The proportion of patients over 75 years with normal D-dimer was doubled (27.9% vs 12.3%). Conclusions:?Our study shows that age-adjusted D-dimer had low nLR allowing its use as a rule-out PE strategy in non-high pre-test clinical probability patients; as well using Vidas(®) , Liatest(®) or MDA(®) assays. This age-adjusted cut-off increased clinical usefulness of D-Dimer in older patients. A large prospective study is required to confirm these results. © 2012 International Society on Thrombosis and Haemostasis.
PMID: 22568451 [PubMed - as supplied by publisher]