Effect of a Retrievable Inferior Vena Cava Filter Plus Anticoagulation vs. Anticoagulation Alone on Risk of Recurrent Pulmonary Embolism: A Randomized Clinical Trial

Importance

Although retrievable inferior vena cava filters are frequently used in addition to anticoagulation in patients with acute venous thromboembolism, their benefit−risk ratio is unclear.

Objective

To evaluate the efficacy and safety of retrievable vena cava filters plus anticoagulation versus anticoagulation alone for preventing pulmonary embolism recurrence in patients presenting with acute pulmonary embolism and a high risk of recurrence.

Design, Setting, and Participants

Randomized, open-label, blinded endpoint trial (PREPIC2) with 6-month follow-up conducted from August 2006 to January 2013. Hospitalized patients with acute, symptomatic pulmonary embolism associated with lower-limb vein thrombosis and at least one criterion for severity were assigned to retrievable inferior vena cava filter implantation plus anticoagulation (filter group; n = 200) or anticoagulation alone with no filter implantation (control group; n = 199). Initial hospitalization with ambulatory follow-up occurred in 17 centers in France.

<target id="page_296" target-type="page">296</target>Interventions

Full-dose anticoagulation for at least 6 months in all patients. Insertion of a retrievable inferior vena cava filter in patients randomized to the filter group. Filter retrieval was planned at 3 months from placement.

Main Outcomes and Measures

Primary efficacy outcome was symptomatic recurrent pulmonary embolism at 3 months. Secondary outcomes were recurrent pulmonary embolism at 6 months, symptomatic deep vein thrombosis, major bleeding, death at 3 and 6 months, and filter complications.

Results

In the filter group, the filter was successfully inserted in 193 patients and was retrieved as planned in 153 of the 164 patients in whom retrieval was attempted. By 3 months, recurrent pulmonary embolism had occurred in six patients (3.0%; all fatal) in the filter group and in three patients (1.5%; two fatal) in the control group (relative risk with filter, 2.00 [95% CI, 0.51–7.89]; P = .50). Results were similar at 6 months. No difference was observed between the two groups regarding the other outcomes. Filter thrombosis occurred in three patients.

Conclusions and Relevance

Among hospitalized patients with severe acute pulmonary embolism, the use of a retrievable inferior vena cava filter plus anticoagulation compared with anticoagulation alone did not reduce the risk of symptomatic recurrent pulmonary embolism at 3 months. These findings do not support the use of this type of filter in patients who can be treated with anticoagulation.