Skip to Main Content
Is Aspirin Suff..

+

After treatment for an idiopathic or unprovoked venous thromboembolism (VTE) the risk of recurrence remains high with a 10% recurrence rate after the first year and 30% recurrence rate after five years.1 Current Chest guidelines state that after the initial three-month treatment for unprovoked VTE, the risk versus benefit for the use of extended anticoagulant therapy must be evaluated. Extended or indefinite therapy with a vitamin K antagonist (warfarin) is recommended for first unprovoked proximal deep vein thrombosis (DVT) or pulmonary embolism (PE) in patients who have low or moderate bleeding risk (Grade 2B).1 However, warfarin increases the risk of bleeding, requires frequent monitoring and dose adjustment, and interacts with many medications. The initiation and propagation of VTE develops through platelets; therefore, antiplatelet therapy may play a role in preventing VTE.2 The combination of aspirin and dipyridamole has previously shown a decreased frequency of VTE when used for primary or secondary prevention.3,4 In addition, aspirin has been shown to be protective in the primary prevention of VTE.5 However, trials evaluating the efficacy of aspirin monotherapy for the secondary prevention of VTE are lacking.6

+

Becattini and colleagues conducted the Aspirin for the Prevention of Recurrent Venous Thromboembolism (the Warfarin and Aspirin [WARFASA]) study to assess the clinical benefit of aspirin for the prevention of VTE recurrence in patients with an unprovoked VTE.7 Patients were included if they were diagnosed with their first-ever VTE, including DVT or PE, and were treated with vitamin K antagonists for 6-18 months. Patients were excluded if they had a high risk of bleeding, indications for long-term anticoagulant therapy other than VTE, established atherosclerosis requiring aspirin or anti-platelet therapy, or VTE associated with estrogen use.8 Patients were treated with either aspirin 100 mg a day or placebo and followed for an average of two years. The primary efficacy outcome was recurrence of VTE and the primary safety outcome was major bleeding.7

+

During this trial, 205 patients received aspirin and 197 received placebo; there were no significant differences in baseline characteristics. After a median study period of 24.6 months, there was a total of 71 patients with VTE recurrence (44 DVT and 27 PE), equating to 8.6% per year. Of the 71 recurrences, 28 out of the 205 patients in the aspirin group had a recurrence and 43 out of 197 patients in the placebo group had a recurrence (6.6% vs. 11.2% per year; hazard ratio 0.58; P=0.02). Aspirin treatment was shown to reduce the risk of VTE recurrence with a number needed to treat of 12 patients for two years to prevent one VTE. Aspirin continued to demonstrate a benefit when results were adjusted for age, sex, index event (PE or DVT), and duration of initial anticoagulant treatment. Both groups had similar safety outcomes; one patient in each group had a nonfatal major bleed and three patients in each group experienced non-major bleeding. There was not a significance difference in deaths between ...

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.