接受低分子量肝素或普通肝素治疗的患者发生肝素诱导的血小板减少症。

Heparin-induced thrombocytopenia in patients treated with low-molecular-weight heparin or unfractionated heparin.

作者信息

Warkentin T E, Levine M N, Hirsh J, Horsewood P, Roberts R S, Gent M, Kelton J G

机构信息

Department of Pathology, McMaster University, Hamilton, Ontario, Canada.

出版信息

N Engl J Med. 1995 May 18;332(20):1330-5. doi: 10.1056/NEJM199505183322003.

DOI:10.1056/NEJM199505183322003

PMID:7715641

Abstract

BACKGROUND

Heparin-induced thrombocytopenia, defined by the presence of heparin-dependent IgG antibodies, typically occurs five or more days after the start of heparin therapy and can be complicated by thrombotic events. The frequency of heparin-induced thrombocytopenia and of heparin-dependent IgG antibodies, as well as the relative risk of each in patients given low-molecular-weight heparin, is unknown.

METHODS

We obtained daily platelet counts in 665 patients in a randomized, double-blind clinical trial comparing unfractionated heparin with low-molecular-weight heparin as prophylaxis after hip surgery. Heparin-induced thrombocytopenia was defined as a decrease in the platelet count below 150,000 per cubic millimeter that began five or more days after the start of heparin therapy, and a positive test for heparin-dependent IgG antibodies. We also tested a representative subgroup of 387 patients for heparin-dependent IgG antibodies regardless of their platelet counts.

RESULTS

Heparin-induced thrombocytopenia occurred in 9 of 332 patients who received unfractionated heparin and in none of 333 patients who received low-molecular-weight heparin (2.7 percent vs. 0 percent; P = 0.0018). Eight of the 9 patients with heparin-induced thrombocytopenia also had one or more thrombotic events (venous in 7 and arterial in 1), as compared with 117 of 656 patients without heparin-induced thrombocytopenia (88.9 percent vs. 17.8 percent; odds ratio, 36.9; 95 percent confidence interval, 4.8 to 1638; P < 0.001). In the subgroup of 387 patients, the frequency of heparin-dependent IgG antibodies was higher among patients who received unfractionated heparin (7.8 percent, vs. 2.2 percent among patients who received low-molecular-weight heparin; P = 0.02).

CONCLUSIONS

Heparin-induced thrombocytopenia, associated thrombotic events, and heparin-dependent IgG antibodies are more common in patients treated with unfractionated heparin than in those treated with low-molecular-weight heparin.

摘要

背景

肝素诱导的血小板减少症，由肝素依赖性IgG抗体的存在所定义，通常在肝素治疗开始五天或更久之后出现，并且可能并发血栓形成事件。肝素诱导的血小板减少症及肝素依赖性IgG抗体的发生率，以及在接受低分子量肝素治疗的患者中各自的相对风险尚不清楚。

方法

在一项随机双盲临床试验中，我们获取了665例髋关节手术后接受普通肝素与低分子量肝素预防治疗患者的每日血小板计数。肝素诱导的血小板减少症定义为肝素治疗开始五天或更久之后血小板计数降至每立方毫米150,000以下，且肝素依赖性IgG抗体检测呈阳性。我们还对387例患者的一个代表性亚组进行了肝素依赖性IgG抗体检测，无论其血小板计数如何。

结果

332例接受普通肝素治疗的患者中有9例发生肝素诱导的血小板减少症，而333例接受低分子量肝素治疗的患者中无一例发生（2.7%对0%；P = 0.0018）。9例肝素诱导的血小板减少症患者中有8例还发生了一次或多次血栓形成事件（7例为静脉血栓，1例为动脉血栓），而656例未发生肝素诱导的血小板减少症的患者中有117例发生（88.9%对17.8%；优势比为36.9；95%置信区间为4.8至1638；P < 0.001）。在387例患者的亚组中，接受普通肝素治疗的患者中肝素依赖性IgG抗体的发生率更高（7.8%，而接受低分子量肝素治疗的患者中为2.2%；P = 0.02）。