Retrievable inferior vena cava filter plus anticoagulation vs anticoagulation alone
PREPIC2 trial design and results
Design
Randomised, open-label trial
Treatment
Retrievable inferior vena cava filter plus anticoagulation
Control
Anticoagulation alone
Population
399 patients with acute pulmonary embolism at high risk of recurrence
Follow-up
6 months
Primary endpoint
Recurrent pulmonary embolism at 3 months
Result
Recurrent PE by 3 months in 6 of 200 (3.0%, all fatal) with a filter versus 3 of 199 (1.5%, 2 fatal) without — relative risk 2.00 (95% CI 0.51 to 7.89, p=0.50). Results were similar at 6 months and no other outcome differed. Filter thrombosis occurred in 3 patients. The filter was retrieved as planned in 153 of 164 attempts.
Secondary endpoints
Recurrence at 6 months, mortality, filter complications
By 3 months, recurrent pulmonary embolism had occurred in 6 patients (3.0%; all fatal) in the filter group and in 3 patients (1.5%; 2 fatal) in the control group.
The trial authors, in the published abstract
How it has aged
Filters remain widely inserted despite this. The trial does not address the one indication that survives it — patients who genuinely cannot be anticoagulated — because everyone in it was anticoagulated. That distinction is where filter use is still defensible, and where it usually is not.
Publications
Effect of a retrievable inferior vena cava filter plus anticoagulation vs anticoagulation alone on risk of recurrent pulmonary embolism: a randomized clinical trial
Mismetti P, Laporte S, Pellerin O, et al. Effect of a retrievable inferior vena cava filter plus anticoagulation vs anticoagulation alone on risk of recurrent pulmonary embolism: a randomized clinical trial. JAMA 2015 Apr 28;313(16):1627-35.
No reduction in recurrent pulmonary embolism at 3 or 6 months