3:00 PM Abstract No. 51 The influence of inferior vena cava filters on the rate of pulmonary embolism in patients with deep venous thrombosis: a population-based study

Abstract

Inferior vena cava (IVC) filters are placed to reduce pulmonary embolism (PE) rates in patients with lower extremity deep venous thrombosis (DVT), though the evidence supporting this practice is limited. The purpose of this study was to evaluate the influence of IVC filter placement on preventing the development of PE in patients with DVT. Using administrative data from all discharges from acute care hospitals in California (2005-2011) and Florida (2005-2014), patients with an initial presentation of DVT without PE were identified. All hospital visits for these patients were then evaluated for the placement of an IVC filter, the development of PE, as well as bleeding and venous thrombosis risk factors. The influence of IVC filter placement on PE rates was estimated using a propensity score matching algorithm. A total of 256,923 patients were identified who accounted for 1,590,610 hospital encounters. 72,383 (28%) patients underwent IVC filter placement; 59,016 (23.0%) underwent IVC filter placement within 30 days of initial DVT diagnosis. IVC filter patients had higher rates of bleeding risk factors including intracranial hemorrhage (4.9 vs 2%, P < 0.001), GI bleed (10.5 vs 5.9%, P < 0.001), and hematuria (4.4 vs 2.3%, P < 0.001). IVC filter patients had higher rates of proximal DVT (54.2% vs 46.1%, P < 0.001) as well as thrombosis risk factors including malignancy (19.7 vs 17.4%, P < 0.001), lower extremity fracture (1.9 vs 0.9%, P < 0.001), and coagulopathies (11.3% vs 8.5%, P < 0.001). A total of 10,432 (4.1%) patients were diagnosed with PE after the initial DVT presentation. After adjusting for these risk factors as well as anticoagulation use by a propensity matching algorithm, patients who received an IVC filter were noted to have a significantly lower rate of PE (3.9% vs 6.7%, P < 0.001) than patients who did not receive an IVC filter. In patients with DVT and bleeding risk factors, IVC filter placement is associated with a decreased rate of pulmonary embolism.Tabled 1IVC FilterNo IVC FilterP ValueAge (median)7470< 0.001Gender (% female)53520.003Intracranial hemorrhage (%)4.92.0< 0.001GI bleed (%)10.55.9< 0.001Hematuria (%)4.42.3< 0.001Proximal DVT (%)54.246.1< 0.001Malignancy (%)19.717.4< 0.001Leg fracture (%)1.90.9< 0.001Coagulopathy (%)11.38.5< 0.001 Open table in a new tab