The two trials enrolled patients with a rst unprovoked VTE who did not have an increased risk of bleeding; patients for whom these guidelines have suggested extended anticoagulant therapy. Extended anticoagulant therapy is expected to reduce recurrent VTE by more than 80% and extended NOAC therapy may be associated with the same risk of bleeding as aspirin.49,50 If patients with a rst unprovoked VTE decline extended anticoagulant therapy because they have risk factors for bleeding or because they have a lower than average risk of recurrence, the net bene t of aspirin therapy is expected to be less than in the two trials that evaluated aspirin for extended treatment of VTE. Based on indirect comparisons, we expect the net bene t of extended anticoagulant therapy in patients with unprovoked VTE to be substantially greater than the bene ts of extended aspirin therapy.49 Consequently, we do not consider aspirin a reasonable alternative to anticoagulant therapy in patients who want extended therapy. However, if a patient has decided to stop 332 Evidence-Based Medicine [ 1 4 9 # 2 C H E S T F E B R U A R Y 2 0 1 6 ] anticoagulants, prevention of recurrent VTE is one of the bene ts of aspirin (may also include reductions in arterial thrombosis and colon cancer) that needs to be balanced against aspirin s risk of bleeding and inconvenience. Use of aspirin should also be reevaluated when patients with VTE stop anticoagulant therapy because aspirin may have been stopped when anticoagulants were started (Table 13, e-Table 14). *12. In patients with an unprovoked proximal DVT or PE who are stopping anticoagulant therapy and do not have a contraindication to aspirin, we suggest aspirin over no aspirin to prevent recurrent VTE (Grade 2B). 