Assessment of the Safety and Efficiency of Using an Age-Adjusted D-dimer Threshold to Exclude Suspected Pulmonary Embolism

作者：Woller Scott C^*; Stevens Scott M; Adams Daniel M; Evans R Scott; Lloyd James F; Snow Gregory L; Bledsoe Joseph R; Gay David Z; Patten Richard M; Aston Valerie T; Elliott C Gregory

来源：Chest, 2014, 146(6): 1444-1451.

DOI：10.1378/chest.13-2386

BACKGROUND: D-dimer levels increase with age, and research has suggested that using an age-adjusted D-dimer threshold may improve diagnostic efficiency without compromising safety. The objective of this study was to assess the safety of using an age-adjusted D-dimer threshold in the workup of patients with suspected pulmonary embolism (PE).
METHODS: We report the outcomes of 923 patients aged. 50 years presenting to our ED with suspected PE, a calculated Revised Geneva Score (RGS), and a D-dimer test. All patients underwent CT pulmonary angiography (CTPA). We compared the false-negative rate for PE of a conventional D-dimer threshold with an age-adjusted D-dimer threshold and report the proportion of patients for whom an age-adjusted D-dimer threshold would obviate the need for CTPA.
RESULTS: Among 104 patients with a negative conventional D-dimer test result and an RGS <= 10, no PE was observed within 90 days (false-negative rate, 0%; 95% CI, 0%-2.8%). Among 273 patients with a negative age-adjusted D-dimer result and an RGS <= 10, four PEs were observed within 90 days (false-negative rate, 1.5%; 95% CI, 0.4%-3.7%). We observed an 18.3% (95% CI, 15.9%-21.0%) absolute reduction in the proportion of patients aged. 50 years who would merit CTPA by using an age-adjusted D-dimer threshold compared with a conventional D-dimer threshold.
CONCLUSIONS: Use of an age-adjusted D-dimer threshold reduces imaging among patients aged. 50 years with an RGS <= 10. Although the adoption of an age-adjusted D-dimer threshold is probably safe, the CIs surrounding the additional 1.5% of PEs missed necessitate prospective study before this practice can be adopted into routine clinical care.

• 出版日期2014-12