Аспирин предотвращает риск развития рецидива венозного тромбоза

[Dr.Vad]

В недавней НЕЙМовской публикации доктора из Италии представили результаты исследования WARFASA: пациенты с идиопатическим эпизодом венозного тромбоза после проведения стандартного лечения варфарином в течение 6-18 мес. были рандомизированы на 100 мг аспирина или плацебо и наблюдались в течение 2 лет, назначение аспирина снизило риск рецидива тромбоза на 40%: повторный тромбоз случился у 6.6% на аспирине и 11.2% на плацебе в год; (hazard ratio, 0.58; 95% confidence interval [CI], 0.36 to 0.93)... большие кровотечения были по 1 в каждой группе и и малых по 3...

N Engl J Med. 2012 May 24;366(21):1959-67.
Aspirin for preventing the recurrence of venous thromboembolism.
Becattini C, Agnelli G, Schenone A, Eichinger S, Bucherini E, Silingardi M, Bianchi M, Moia M, Ageno W, Vandelli MR, Grandone E, Prandoni P; WARFASA Investigators.
Division of Internal and Cardiovascular Medicine and Stroke Unit, Department of Internal Medicine, University of Perugia, Perugia, Italy.

BACKGROUND: About 20% of patients with unprovoked venous thromboembolism have a recurrence within 2 years after the withdrawal of oral anticoagulant therapy. Extending anticoagulation prevents recurrences but is associated with increased bleeding. The benefit of aspirin for the prevention of recurrent venous thromboembolism is unknown.

METHODS: In this multicenter, investigator-initiated, double-blind study, patients with first-ever unprovoked venous thromboembolism who had completed 6 to 18 months of oral anticoagulant treatment were randomly assigned to aspirin, 100 mg daily, or placebo for 2 years, with the option of extending the study treatment. The primary efficacy outcome was recurrence of venous thromboembolism, and major bleeding was the primary safety outcome.

RESULTS: Venous thromboembolism recurred in 28 of the 205 patients who received aspirin and in 43 of the 197 patients who received placebo (6.6% vs. 11.2% per year; hazard ratio, 0.58; 95% confidence interval [CI], 0.36 to 0.93) (median study period, 24.6 months). During a median treatment period of 23.9 months, 23 patients taking aspirin and 39 taking placebo had a recurrence (5.9% vs. 11.0% per year; hazard ratio, 0.55; 95% CI, 0.33 to 0.92). One patient in each treatment group had a major bleeding episode. Adverse events were similar in the two groups.

CONCLUSIONS: Aspirin reduced the risk of recurrence when given to patients with unprovoked venous thromboembolism who had discontinued anticoagulant treatment, with no apparent increase in the risk of major bleeding. (Funded by the University of Perugia and others; WARFASA ClinicalTrials.gov number, NCT00222677).

В редакционном комментарии отмечается, что 35-40% снижение риска тромбоза отмечалось и в предыдущих публикациях, тогда как варфарин снижает риск рецидива тромбоза на 60-90% (но и добавляет риск экстра-кровотечений)...

еще один подобный трайл проводится в Австралии и его результаты будут к концу 2012 - началу 2013 года:

The ongoing Aspirin to Prevent Recurrent Venous Thromboembolism (ASPIRE) study (Australian New Zealand Clinical Trials Registry number, ACTRN012605000004662) has recruited 822 patients with a first unprovoked event, as documented by means of objective testing, who have received warfarin anticoagulant therapy for 3 to 6 months (but not longer than 12 months). Patients have been randomly assigned to either aspirin (100 mg daily) or placebo for a median of 3 years and are being followed for a first occurrence of symptomatic and objectively confirmed deep-vein thrombosis or nonfatal or fatal pulmonary embolism with the use of an intention-to-treat approach. Results of this study are expected during 2012.