In patients with acute proximal DVT of the leg, we suggest anticoagulant therapy alone over CDT (Grade 2C). Remarks: Patients who are most likely to bene t from CDT (see text), who attach a high value to prevention of PTS, and a lower value to the initial complexity, cost, and risk of bleeding with CDT, are likely to choose CDT over anticoagulation alone. Role of IVC Filter in Addition to Anticoagulation for Acute DVT or PE Summary of the Evidence Our recommendation in AT9 was primarily based on ndings of the Prevention du Risque d Embolie Pulmonaire par Interruption Cave (PREPIC) randomized which showed that placement of a permanent IVC lter increased DVT, decreased PE, and did not in uence VTE(DVTand PEcombined)ormortality.Since then, several registries have suggested that IVC lters can reduce early mortality inpatients with acute VTE, although this evidence has been questioned.97-101 The recently published PREPIC 2 randomized trial found that placement of an IVC lter for 3 months did not reduce recurrent PE, including fatal PE, in anticoagulated patients with PE and DVT who had additional risk factors for This newevidence is consistent with our recommendations in AT9. However, because it is uncertain if there is bene t to placement of an IVC lter in anticoagulated patients with severe PE (eg, with hypotension), and this is done by some experts, our recommendation against insertion of an IVC lter in patients with acute PE who are anticoagulated may not apply to this select subgroup of patients. Although the PREPIC 2 study has improved the quality of evidence for this recommendation, overall quality is still moderate because of imprecision (Table 16, e-Table 16). 