PDF(Pubmed)
Abstract：
Monitoring of anticoagulant activity of unfractionated heparin (UFH) is primarily done with activated partial thromboplastin time (aPTT), which is affected by many factors. Anti-Xa assays are considered to overcome these factors and may provide a better method for monitoring patients on UFH with a narrow therapeutic range. This study aimed to compare the effectiveness of aPTT and anti-Xa assays in UFH monitoring. A prospective non-randomized study was carried out in two stages: first, the anti-Xa assay was standardized using kit instructions; each sample was then analyzed by both tests. The outcomes of the two assays were compared and assessed for agreement of maintaining therapeutic anticoagulant levels. These levels for anti-Xa assay were between 0.3 and 0.7 IU/ml, while it was 1.5-2.5 times the control for aPTT assay. Below this range was regarded as subtherapeutic, and above this as supratherapeutic. A total of 90 samples were tested and analyzed using both assays. Most of them (> 70%) were noted to be in subtherapeutic levels with both tests. The overall concordance was 73.3%, and the estimated kappa value was 0.483 (0.396-0.57). The correlation between aPTT and anti-Xa assay was 0.74 (p < 0.001). With anti-Xa levels in the therapeutic range, aPTT levels were in subtherapeutic in 60% and supratherapeutic in 13.3% cases. Although both the testing strategies had a good agreement and correlation, discordance was observed in interpretative values with anti-Xa levels in therapeutic range and aPTT levels in non-therapeutic range. Its clinical implications need to be evaluated further in future studies.
摘要：
普通肝素(UFH)抗凝活性的监测主要通过活化部分凝血活酶时间(aPTT)来完成,这受到许多因素的影响。抗Xa测定被认为克服了这些因素,并且可以提供用于以窄治疗范围监测UFH患者的更好方法。本研究旨在比较aPTT和抗Xa测定在UFH监测中的有效性。一项前瞻性非随机研究分两个阶段进行：第一，使用试剂盒说明书将抗Xa试验标准化;然后通过两种试验对每个样品进行分析.比较两种测定的结果并评估维持治疗性抗凝血剂水平的一致性。抗Xa测定的这些水平在0.3和0.7IU/ml之间，而aPTT测定是对照的1.5-2.5倍。低于这个范围被认为是亚治疗性的，除此之外，作为超常治疗。使用两种测定法测试和分析总共90个样品。在两种测试中，大多数（>70％）都处于亚治疗水平。总体一致性为73.3%,估计kappa值为0.483（0.396-0.57）。aPTT和抗Xa测定之间的相关性为0.74(p<0.001)。抗Xa水平在治疗范围内，aPTT水平在60%的病例中处于亚治疗状态，在13.3%的病例中处于超治疗状态。虽然两种测试策略都有很好的一致性和相关性，在抗Xa水平在治疗范围内和aPTT水平在非治疗范围内的解释值方面观察到不一致.其临床意义需要在未来的研究中进一步评估。
