From McMaster University and Hamilton Health Sciences, Hamilton, Ontario, Canada.
Ann Intern Med. 2017 Aug 1;167(3):170-180. doi: 10.7326/M17-0284. Epub 2017 Jun 27.
Patients with essential thrombocythemia (ET) are at high risk for both thrombosis and hemorrhage.
To evaluate the risks and benefits of antithrombotic therapy in adults with ET.
Multiple databases, including MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials, through 4 March 2017.
Randomized and observational studies of antiplatelet or anticoagulant therapy, published in any language and reporting thrombotic or hemorrhagic events.
Two reviewers independently extracted data, assessed risk of bias, and graded certainty of evidence.
No relevant randomized trials were identified. Twenty-four observational studies (18 comparative and 6 single-group) involving 6153 patients followed for 31 711 patient-years were reviewed; most were deemed to have high risk of bias. Most patients receiving antiplatelet therapy (3613 of 4527 [80%]) received low-dose aspirin (50 to 150 mg/d); 914 (20%) received high-dose aspirin (300 to 600 mg/d), dipyridamole, or other agents. Overall, findings were inconsistent and imprecise. The reported incidence rates of thrombosis, any bleeding, and major bleeding without antiplatelet therapy ranged from 5 to 110 (median, 20), from 3 to 39 (median, 8), and from 2 to 53 (median, 6) cases per 1000 patient-years, respectively. The reported relative risks for thrombosis, any bleeding, and major bleeding with antiplatelet therapy compared with none ranged from 0.26 to 3.48 (median, 0.74), from 0.48 to 11.04 (median, 1.95), and from 0.48 to 5.17 (median, 1.30), respectively. Certainty of evidence was rated low or very low for all outcomes.
No randomized trials, no extractable data on anticoagulants, lack of uniform bleeding definitions, and systematic reporting of outcomes.
Available evidence about the risk-benefit ratio of antiplatelet therapy in adults with ET is highly uncertain.
Regional Medical Associates. (PROSPERO: CRD42015027051).
原发性血小板增多症（ET）患者存在血栓形成和出血的高风险。
评估抗血栓治疗对 ET 成人患者的风险和获益。
多个数据库，包括 MEDLINE、EMBASE 和 Cochrane 对照试验中心注册库，检索日期截至 2017 年 3 月 4 日。
抗血小板或抗凝治疗的随机和观察性研究，发表于任何语言的文献，并报告血栓形成或出血事件。
两名审阅者独立提取数据、评估偏倚风险并对证据质量进行分级。
未发现相关的随机试验。共纳入 24 项观察性研究（18 项为比较研究，6 项为单组研究），共纳入 6153 例患者，随访 31711 患者-年；大多数研究被认为存在高偏倚风险。大多数接受抗血小板治疗的患者（4527 例中的 3613 例[80%]）接受低剂量阿司匹林（50150 mg/d）；914 例（20%）接受高剂量阿司匹林（300600 mg/d）、双嘧达莫或其他药物。总体而言，研究结果不一致且不精确。未接受抗血小板治疗患者的血栓形成、任何出血和无抗血小板治疗的大出血发生率范围为 5110 例/1000 患者-年（中位数 20）、339 例/1000 患者-年（中位数 8）和 253 例/1000 患者-年（中位数 6），接受抗血小板治疗与未治疗相比，其血栓形成、任何出血和大出血的相对风险范围分别为 0.263.48（中位数 0.74）、0.4811.04（中位数 1.95）和 0.485.17（中位数 1.30）。所有结局的证据确定性均为低或极低。
无随机试验，无法提取抗凝剂数据，缺乏统一的出血定义，以及结局的系统报告。
目前关于抗血小板治疗对 ET 成人患者风险-获益比的证据高度不确定。
地区医疗协会。（PROSPERO：CRD42015027051）
