Parent Florence, Maître Sophie, Meyer Guy, Raherison Chantal, Mal Hervé, Lancar Rémi, Couturaud Francis, Mottier Dominique, Girard Philippe, Simonneau Gérald, Leroyer Christophe
Hôpital Antoine Béclère, Assistance Publique Hôpitaux de Paris, Clamart, France.
Thromb Res. 2007;120(2):195-200. doi: 10.1016/j.thromres.2006.09.012. Epub 2006 Oct 24.
D-dimer tests are used in various diagnostic strategies to exclude pulmonary embolism (PE). However, their role as an exclusionary first-line test is still uncertain, mainly because accuracy of the test varies according to the assay and the studied population.
The aim of this multicentre study was to evaluate the accuracy of D-dimer testing in patients with suspected PE. Diagnosis of PE was based on pre-test clinical probability (PCP) evaluation and both single-detector spiral CT (CT) and lower limbs compression ultrasonography (CUS). Lung scanning and/or pulmonary angiography was mandatory when CT or CUS was inconclusive and when both CT and CUS were normal in a patient with a high PCP. All patients were followed-up for 3 months, looking for VTE recurrence. D-dimers were collected within 24 h of inclusion and stored in each local hematology unit, to be analyzed at the end of all inclusions; physicians in charge of the patient were blinded to D-dimer results.
Three hundred and fifty two patients were included in 4 centres. Prevalence of PE was 38.6%. PCP was low in 82 (23.3%), intermediate in 176 (50%) and high in 94 (26.7%) patients. Sensitivity of D-dimer was 96.3% (95% CI: 93-99) and negative predictive value reached 94.4% (95% CI: 90-99). Five patients with a confirmed PE had a D-dimer level below 500 ng/ml (two patients with a high PCP). Among 258 patients with low or intermediate PCP, 80 (31%) had a negative D-dimer test result; three of them had a false negative result and the number needed to test was 3.3. Among 94 patients with a high PCP, 9 had a negative D-dimer test result; two of them had a false negative result and the number needed to test was 13.5.
These results confirm that rapid assays used in this study can safely exclude PE in first-line testing only in non-high CP patients.
D-二聚体检测被用于多种诊断策略中以排除肺栓塞（PE）。然而，其作为排除性一线检测的作用仍不确定，主要是因为检测的准确性因检测方法和研究人群而异。
这项多中心研究的目的是评估D-二聚体检测在疑似PE患者中的准确性。PE的诊断基于检测前临床概率（PCP）评估以及单排螺旋CT（CT）和下肢加压超声检查（CUS）。当CT或CUS结果不明确时，以及PCP高的患者CT和CUS均正常时，必须进行肺部扫描和/或肺血管造影。所有患者随访3个月，观察VTE复发情况。D-二聚体在纳入后24小时内采集，并储存在各当地血液学单位，在所有纳入结束时进行分析；负责患者的医生对D-二聚体结果不知情。
4个中心共纳入352例患者。PE的患病率为38.6%。82例（23.3%）患者PCP低，176例（50%）患者PCP中等，94例（26.7%）患者PCP高。D-二聚体的敏感性为96.3%（95%CI：93-99），阴性预测值达94.4%（95%CI：90-99）。5例确诊PE的患者D-二聚体水平低于500 ng/ml（2例PCP高的患者）。在258例PCP低或中等的患者中，80例（31%）D-二聚体检测结果为阴性；其中3例为假阴性结果，检测所需例数为3.3。在94例PCP高的患者中，9例D-二聚体检测结果为阴性；其中2例为假阴性结果，检测所需例数为13.5。
这些结果证实，本研究中使用的快速检测方法仅在非高PCP患者的一线检测中可安全地排除PE。
