Division of Hematology-Oncology, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE.
Eur J Haematol. 2013 Nov;91(5):437-41. doi: 10.1111/ejh.12179. Epub 2013 Aug 20.
Large licensing trials did not find any association between the use of fondaparinux and the development of heparin-induced thrombocytopenia (HIT). Fondaparinux is in fact recommended as an option for the management of HIT. Since the first report of fondaparinux-associated HIT in 2007, additional reports have been published. However, the rarity of these cases, differences in case definition, and lack of larger case series have prevented better understanding of this disease. The objective of this study was to determine the clinical manifestations of fondaparinux-associated HIT, the predictive value of pretest probability (4Ts) scoring system, and the outcomes associated with current management.
Using several search terms, we reviewed all cases of fondaparinux-associated HIT reported and indexed in PubMed till May 2013. All references were also checked for additional reports. We categorized the cases of fondaparinux-associated HIT as confirmed, probable, and possible based on our case definition.
A total of eight cases of fondaparinux-associated HIT were identified. Fondaparinux-associated HIT occurred in the setting of pro-inflammatory state, prior HIT, or exposure to heparin products. Bilateral adrenal hemorrhage or infarct, reflecting hypercoagulability or disseminated intravascular coagulation, was seen in 25% of patients. The pretest probability (4Ts) scoring system used for HIT appears to correctly risk stratify all the cases. Although functional assays can be used for the diagnosis, in the presence of recent exposure to heparin products, only the demonstration of fondaparinux-dependent platelet activation should be considered confirmatory. Non-heparin anticoagulants are effective therapy; however, one-third of the patients had poor outcomes.
The risk of fondaparinux-associated HIT, although low is real, which along with documented cases of fondaparinux failure mandate its cautious use in the management of HIT.
大型授权试验并未发现使用磺达肝素钠与肝素诱导的血小板减少症（HIT）的发展之间存在任何关联。磺达肝素钠实际上被推荐作为 HIT 管理的一种选择。自 2007 年首次报道磺达肝素钠相关性 HIT 以来，已有更多的报道发表。然而，由于这些病例罕见，病例定义的差异以及缺乏更大的病例系列，阻碍了对这种疾病的更好理解。本研究的目的是确定磺达肝素钠相关性 HIT 的临床表现，预测值（4Ts）评分系统和当前管理相关的结果。
我们使用了几个搜索词，回顾了截至 2013 年 5 月在 PubMed 中报告和索引的所有磺达肝素钠相关性 HIT 病例。还检查了所有参考文献以获取其他报告。我们根据我们的病例定义将磺达肝素钠相关性 HIT 病例分为确诊、可能和可能。
共发现 8 例磺达肝素钠相关性 HIT。磺达肝素钠相关性 HIT 发生在促炎状态、先前的 HIT 或暴露于肝素产品的情况下。25％的患者出现双侧肾上腺出血或梗死，反映出高凝状态或弥散性血管内凝血。用于 HIT 的测试前概率（4Ts）评分系统似乎可以正确地对所有病例进行风险分层。尽管可以使用功能检测进行诊断，但在最近暴露于肝素产品的情况下，仅应考虑磺达肝素钠依赖性血小板活化的证明为确诊。非肝素抗凝剂是有效的治疗方法；但是，三分之一的患者预后不良。
磺达肝素钠相关性 HIT 的风险虽然较低，但却是真实存在的，这与磺达肝素钠失败的已有案例一起，要求在 HIT 的管理中谨慎使用。
