A Clinical Trial of Vena Caval Filters in the Prevention of Pulmonary Embolism in Patients With Proximal Deep-Vein Thrombosis - PREPIC
The goal of this randomized study was to evaluate the efficacy of venal caval filters, unfractionated heparin (UFH), and low molecular weight heparin (LMWH) in preventing pulmonary embolus among patients with proximal deep-vein thrombosis.
Vena caval filters may be associated with a reduction in pulmonary embolism among patients with proximal deep-vein thrombosis.
Patients Screened: 735
Patients Enrolled: 400
Mean Follow Up: Two years
Acute proximal deep-vein thrombosis, and physician deemed patient at high risk of pulmonary embolism
Placement of previous filter, contraindication to anticoagulant therapy, curative anticoagulant therapy lasting over 48 hours, indication for fibrinolytics, short life expectancy, allergy to iodine, hereditary thrombophilia, severe renal or hepatic failure, pregnancy, or likelihood of noncompliance
Symptomatic or asymptomatic pulmonary embolism within 12 days of randomization by angiography, ventilation-perfusion scan, or strong clinical evidence at autopsy
At two years: symptomatic pulmonary embolism, recurrent deep-vein thrombosis, death, major filter complications, and major bleeding
Vena caval filter (one of four types), LMWH 1 mg/kg every 12 hours, and UFH 5000 IU bolus followed by 500 IU/kg for 8-12 days adjusted to achieve a value of 1.5-2.5
Warfarin was started on day 4 and continued for at least three months, with goal international normalized ratio (INR) 2.0-3.0.
At day 12:
• 1.1% of those in the filter group versus 4.8% of those without filters had pulmonary embolism (p=0.03).
• 1.6% of those in the LMWH group compared with 4.2% of those in the UFH group had pulmonary embolism (p=0.14).
At two years:
• 20.8% of those with filters compared with 11.6% of those without filters had recurrent deep-vein thrombosis (p=0.02).
• No difference in major bleeding or death at 12 days.
Among patients with proximal deep-vein thrombosis, placement of a vena caval filter was associated with a decreased incidence of pulmonary embolism at 12 days, but an increase in recurrent deep-vein thrombosis at two years.
Decousus H, Leizorovicz A, Parent F, et al. A clinical trial of vena caval filters in the prevention of pulmonary embolism in patients with proximal deep-vein thrombosis. Prevention du Risque d'Embolie Pulmonaire par Interruption Cave Study Group. N Engl J Med 1998;338:409-15.
Keywords: Vena Cava Filters, Thrombosis, Heparin, Low-Molecular-Weight, Pulmonary Embolism
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