S. Takach Lapner, Department of Medicine, University of Alberta, 4-112 Clinical Sciences Building, 11350 83 Avenue, Edmonton, AB T6G 2R3, Canada, Tel.: +1 780 407 1584 extension 3, E-mail:
Thromb Haemost. 2017 Oct 5;117(10):1937-1943. doi: 10.1160/TH17-03-0182. Epub 2017 Aug 3.
Two new strategies for interpreting D-dimer results have been proposed: i) using a progressively higher D-dimer threshold with increasing age (age-adjusted strategy) and ii) using a D-dimer threshold in patients with low clinical probability that is twice the threshold used in patients with moderate clinical probability (clinical probability-adjusted strategy). Our objective was to compare the diagnostic accuracy of age-adjusted and clinical probability-adjusted D-dimer interpretation in patients with a low or moderate clinical probability of venous thromboembolism (VTE). We performed a retrospective analysis of clinical data and blood samples from two prospective studies. We compared the negative predictive value (NPV) for VTE, and the proportion of patients with a negative D-dimer result, using two D-dimer interpretation strategies: the age-adjusted strategy, which uses a progressively higher D-dimer threshold with increasing age over 50 years (age in years × 10 µg/L FEU); and the clinical probability-adjusted strategy which uses a D-dimer threshold of 1000 µg/L FEU in patients with low clinical probability and 500 µg/L FEU in patients with moderate clinical probability. A total of 1649 outpatients with low or moderate clinical probability for a first suspected deep vein thrombosis or pulmonary embolism were included. The NPV of both the clinical probability-adjusted strategy (99.7 %) and the age-adjusted strategy (99.6 %) were similar. However, the proportion of patients with a negative result was greater with the clinical probability-adjusted strategy (56.1 % vs, 50.9 %; difference 5.2 %; 95 % CI 3.5 % to 6.8 %). These findings suggest that clinical probability-adjusted D-dimer interpretation is a better way of interpreting D-dimer results compared to age-adjusted interpretation.
提出了两种新的 D-二聚体结果解释策略：i）随着年龄的增加使用逐渐升高的 D-二聚体阈值（年龄调整策略）和 ii）在临床低度可能性的患者中使用两倍于中度临床可能性患者使用的 D-二聚体阈值（临床可能性调整策略）。我们的目的是比较在低度或中度静脉血栓栓塞（VTE）临床可能性的患者中，年龄调整和临床可能性调整的 D-二聚体解释的诊断准确性。我们对两项前瞻性研究的临床数据和血液样本进行了回顾性分析。我们比较了两种 D-二聚体解释策略的阴性预测值（NPV）和阴性 D-二聚体结果的患者比例：年龄调整策略，即随着年龄的增加，50 岁以上的患者使用逐渐升高的 D-二聚体阈值（年龄×10 µg/L FEU）；以及临床可能性调整策略，即临床低度可能性的患者使用 1000 µg/L FEU 的 D-二聚体阈值，而中度临床可能性的患者使用 500 µg/L FEU 的 D-二聚体阈值。共纳入了 1649 名首次疑似深静脉血栓形成或肺栓塞的门诊低度或中度临床可能性患者。临床可能性调整策略（99.7%）和年龄调整策略（99.6%）的 NPV 相似。然而，临床可能性调整策略的阴性结果比例更高（56.1%比 50.9%；差异 5.2%；95%CI 3.5%至 6.8%）。这些发现表明，与年龄调整解释相比，临床可能性调整的 D-二聚体解释是一种更好的 D-二聚体结果解释方法。
