Crippa L, D'Angelo S V, Tomassini L, Rizzi B, D'Alessandro G, D'Angelo A
Coagulation Service, Scientific Institute H San Raffaele, Milan, Italy.
Haematologica. 1997 Jul-Aug;82(4):446-51.
The potential utility of D-dimer measurements for the diagnosis of deep vein thrombosis became evident soon after the development of reliable commercial assays. The purpose of this review is to outline some critical aspects affecting cost-effectiveness of D-dimer measurements in the diagnosis of deep vein thrombosis (DVT).
The authors have been working in this field contributing original papers whose data have been used for this study. In addition, the material analyzed in this article includes papers published in the journals covered by the Science Citation Index and Medline.
D-dimer levels are very sensitive to the process of fibrin formation/dissolution occurring with ongoing thrombosis. However, they may not be highly specific for venous thromboembolism as they are influenced by the presence of comorbid conditions potentially elevating plasma D-dimer (cancer, surgery, infectious diseases). In addition, commercially available ELISA assays, although quantitative and reproducible, cannot be used under emergency conditions because they are time-consuming and suited for batch-processing of plasma samples. Recently, new assays have been introduced which permit fast and quantitative D-dimer estimations in individual patients. We have evaluated the utility of two new rapid assays (LPIA D-dimer. Mitsubishi, and VIDAS D-DIMER, bio-Merieux) in combination with compression real-time-B-mode ultrasonography for the detection of deep vein thrombosis in asymptomatic patients following elective hip replacement and in patients with clinically suspected deep vein thrombosis. In both settings, we identified cut-off values with optimal sensitivity which allow exclusion of deep vein thrombosis in a considerable percentage of patients, with substantial sparing of economic resources. In fact, based on a cost-effectiveness analysis, a diagnostic algorithm combining D-dimers measurement and compression ultrasonography would result in cost-savings ranging from 5% to 55% in patients with high or low clinical pretest probability respectively. However, the specificity of D-dimer measurements for deep vein thrombosis was much higher in symptomatic than in asymptomatic patients. Choice of the cut-off value proved to be dependent on the method as well as on the patient populations studied.
The cost-effectiveness of D-dimers measurement in the diagnosis of asymptomatic DVT remains questionable. Conversely, our data strongly support the utility of D-dimers determinations in the diagnosis of symptomatic DVT. In terms of sparing economic resources, the introduction in the clinical laboratory of the rapid quantitative assays would be highly convenient, because they avoid a source of bias in the interpretation of D-dimers results, are easy to perform and do not require dedicated personnel or instrumentation. Prospective management studies validating the utility of D-dimer measurement in the diagnosis of deep vein thrombosis are urgently needed.
在可靠的商业检测方法出现后不久，D - 二聚体检测在诊断深静脉血栓形成方面的潜在效用就变得明显。本综述的目的是概述影响D - 二聚体检测在诊断深静脉血栓形成（DVT）中成本效益的一些关键方面。
作者一直在该领域工作，贡献了一些原始论文，其数据已用于本研究。此外，本文分析的材料包括发表在《科学引文索引》和《医学索引》所涵盖期刊上的论文。
D - 二聚体水平对正在发生的血栓形成过程中纤维蛋白的形成/溶解过程非常敏感。然而，它们对静脉血栓栓塞可能并非高度特异，因为它们会受到可能升高血浆D - 二聚体的合并症（癌症、手术、传染病）的影响。此外，市售的ELISA检测方法虽然定量且可重复，但由于耗时且适合血浆样本的批量处理，在紧急情况下无法使用。最近，已引入新的检测方法，可对个体患者进行快速定量D - 二聚体评估。我们评估了两种新的快速检测方法（三菱公司的LPIA D - 二聚体和生物梅里埃公司的VIDAS D - DIMER）与实时B型超声压迫检查相结合，用于检测择期髋关节置换术后无症状患者以及临床怀疑有深静脉血栓形成患者的深静脉血栓。在这两种情况下，我们确定了具有最佳敏感性的临界值，可在相当比例的患者中排除深静脉血栓形成，从而大量节省经济资源。事实上，基于成本效益分析，将D - 二聚体检测与超声压迫检查相结合的诊断算法，在临床预测试概率高或低的患者中分别可节省5%至55%的成本。然而，有症状患者中D - 二聚体检测对深静脉血栓形成的特异性远高于无症状患者。临界值的选择证明既取决于方法，也取决于所研究的患者群体。
D - 二聚体检测在无症状DVT诊断中的成本效益仍存在疑问。相反，我们的数据有力地支持了D - 二聚体检测在有症状DVT诊断中的效用。就节省经济资源而言，在临床实验室引入快速定量检测方法将非常方便，因为它们避免了D - 二聚体结果解释中的偏差来源，易于操作，且不需要专门人员或仪器。迫切需要进行前瞻性管理研究，以验证D - 二聚体检测在诊断深静脉血栓形成中的效用。
