Gómez-Jabalera Efrem, Bellmunt Montoya Sergio, Fuentes-Camps Eva, Escudero Rodríguez José Román
1 Vascular Surgery Department, Hospital de la Santa Creu i Sant Pau, Barcelona, Catalunya, Spain.
2 Vascular Surgery Department, Hospital Vall d'Hebron, Barcelona, Catalunya, Spain.
Phlebology. 2018 Aug;33(7):458-463. doi: 10.1177/0268355517718762. Epub 2017 Jul 5.
Objective In the diagnosis of deep vein thrombosis, new D-dimer cut-off values were defined by multiplying 10 µg/L × age. The objective of the present study is to define a more specific age-adjusted value, including the pre-test Wells score, without worsening sensitivity. Methods We designed a case-control study in patients attended in the emergency department with clinically suspected deep vein thrombosis. Demographics, Wells score, D-dimer and ultrasound data were collected. In low and intermediate clinical probability cases for deep vein thrombosis, we determined the specificity and sensitivity (false-negative rates) for the following cut-off values of D-dimer: age × 10 µg/L, age × 15 µg/L, age × 20 µg/L, age × 25 µg/L and age × 30 µg/L. The cut-off value with maximum specificity without any false-negative result (sensitivity 100%) was identified. Results We included 138 consecutive patients, 39.9% were men and the mean age was 71.6 years. Deep vein thrombosis was diagnosed in 16.7% of patients and the Wells score was low in 69.6%, intermediate in 21% and high in 9.4% of patients. Applying the conventional cut-off value of 500 µg/L, the specificity was 21.1% with a sensitivity of 100%. Maintaining 100% sensitivity, the highest specificity was reached with a cut-off value for D-dimer equivalent to the age × 25 µg/L in low-risk patients (67.1% specificity) and the age × 10 µg/L (50% specificity) in intermediate-risk patients. Conclusions In patients with low Wells score, the cut-off value can be raised to age × 25 µg/L in order to rule out deep vein thrombosis without jeopardizing safety. In intermediate-risk patients, the D-dimer cut-off value could be raised to age × 10 µg/L as previously suggested.
目的 在深静脉血栓形成的诊断中，通过将10μg/L乘以年龄来定义新的D-二聚体临界值。本研究的目的是定义一个更具特异性的年龄校正值，包括预检Wells评分，同时不降低敏感性。方法 我们设计了一项病例对照研究，纳入急诊科临床怀疑深静脉血栓形成的患者。收集人口统计学、Wells评分、D-二聚体和超声数据。在深静脉血栓形成的低和中度临床概率病例中，我们确定了以下D-二聚体临界值的特异性和敏感性（假阴性率）：年龄×10μg/L、年龄×15μg/L、年龄×20μg/L、年龄×25μg/L和年龄×30μg/L。确定了无任何假阴性结果（敏感性100%）的最大特异性临界值。结果 我们纳入了138例连续患者，39.9%为男性，平均年龄为71.6岁。16.7%的患者被诊断为深静脉血栓形成，69.6%的患者Wells评分为低，21%为中度，9.4%为高。应用500μg/L的传统临界值，特异性为21.1%，敏感性为100%。保持100%的敏感性，低风险患者中D-二聚体临界值为年龄×25μg/L时特异性最高（67.1%），中度风险患者中为年龄×10μg/L时特异性最高（50%）。结论 在Wells评分低的患者中，临界值可提高到年龄×25μg/L，以排除深静脉血栓形成而不危及安全性。在中度风险患者中，D-二聚体临界值可如先前建议提高到年龄×10μg/L。
