JAMA：阿司匹林治疗可减少复发性静脉血栓栓塞

研究者在《JAMA》杂志上报告，对于在首次无明确原因的静脉血栓栓塞事件后停用抗凝剂治疗的患者，每日阿司匹林治疗可显著降低复发性血栓事件风险。

在这项纳入402例患者的多中心、双盲的阿司匹林预防复发性静脉血栓栓塞[华法林和阿司匹林(WARFASA)]研究中，所有患者在随机化之前完成6~18个月的维生素K拮抗剂口服抗凝治疗。排除有癌症、血栓形成倾向或在抗凝剂治疗期间发生出血的患者，但作者称“估计很大比例(可能为大多数)有首次静脉血栓栓塞发作病史的患者适合将阿司匹林治疗作为二级预防措施”。

意大利佩鲁贾大学的Cecilia Becattini博士在2011年12月的美国血液学会年会上展示了这项研究的结果。该研究结果显示，随机接受阿司匹林治疗者的新发血栓事件发生率为每年6.6%，安慰剂组为每年11.2%。

中位治疗期23.9个月内，阿司匹林和安慰剂组的复发率分别为每年5.9%和11.0%，每组各有1例患者发生大出血(N. Engl. J. Med. 366;21:1959-67)。接受阿司匹林每日治疗患者的血栓复发率降低了40%，且大出血无增加。随机分配至阿司匹林每日100 mg组与安慰剂组患者的不良事件相似。

该研究由佩鲁贾大学、拜耳医药保健公司的一项基金和国际血栓与凝血学会提供的安万特临床研究奖学金（授予Becattini医生）资助。Becattini医生及数位合著者披露与多家医药公司之间存在利益关系，其中包括拜耳公司。

BY JANE SALODOF MACNEIL
Elsevier Global Medical News
Breaking News

Daily aspirin reduced the risk of recurrent blood clots significantly for patients who had stopped anticoagulant therapy after a first unprovoked venous thromboembolism, investigators reported in JAMA.

About a 40% reduction was accomplished without an increase in major bleeding, in the 402-patient Aspirin for the Prevention of Recurrent Venous Thromboembolism (the Warfarin and Aspirin [WARFASA]) study. Adverse events were similar whether patients were randomized to 100 mg of aspirin daily or placebo.

New blood clots occurred at a rate of 6.6% per year in patients randomized to aspirin, compared with 11.2% per year in those given placebo, Dr. Cecilia Becattini and her associates reported. At a median treatment period of 23.9 months, the recurrence rates while taking the study drug were 5.9% and 11.0% per year, respectively, with 1 patient in each group having a major bleed (N. Engl. J. Med. 366;21:1959-67).

All patients had completed 6-18 months of oral anticoagulant treatment with a vitamin K antagonist before randomization in the multicenter, double-blind trial. Patients were not enrolled if they had cancer, thrombophilia, or bleeding during the period of anticoagulant treatment, but the authors wrote that they “estimate that a substantial proportion (probably the majority) of patients with an initial episode of venous thromboembolism would be eligible for aspirin therapy as secondary prevention.”

Dr. Becattini of the University of Perugia (Italy) presented results in December 2011 at the annual meeting of the American Society of Hematology. (Click here for our report, including a video interview with Dr. Becattini.)

The trial received support from the University of Perugia, a grant-in-aid from Bayer HealthCare, and an Aventis Fellowship for Clinical Research from the International Society of Thrombosis and Haemostasis (to Dr. Becattini). Dr. Becattini and several coauthors disclosed relationships with various drug companies, including Bayer.

Wait for the ASPIRE Study

In an accompanying editorial, Dr. Richard C. Becker wrote that the study findings “are compelling and may signal an important step in the evolution of care; however, confirmatory studies will be required to establish a role in daily clinical practice for the use of aspirin among patients who are at high risk for bleeding due to anticoagulant therapy or for whom ongoing investigations identify and subsequently validate a clinical or biomarker-based profile associated with a low risk of recurring venous thromboembolism” (N. Engl. J. Med. 366;21:2028-30).

He called attention to the ongoing Aspirin to Prevent Recurrent Venous Thromboembolism (ASPIRE) study. “A prospectively planned, combined analysis of the ASPIRE and WARFASA trials ACTRN12611000684921) may provide more reliable evidence of the effect of aspirin in patients with first unprovoked venous thromboembolism,” said Dr. Becker.

Dr. Becker is at the Duke Clinical Research Institute, Duke University Medical Center, Durham, North Carolina. He disclosed relationships with seven pharmaceutical companies.