03:18 PM Abstract No. 153 The influence of IVC filters on the rate of pulmonary embolism in cancer patients with deep venous thrombosis: a population-based study

Abstract

Inferior vena cava (IVC) filters are placed to reduce pulmonary embolism (PE) in patients with lower extremity deep venous thrombosis (DVT). The purpose of this population based study was to evaluate the influence of IVC filters in the prevention of PE for cancer patients with DVT. Using administrative data from all discharges from acute care hospitals in California (2005-2011) and Florida (2005-2014), cancer patients with DVT were identified. All subsequent hospital visits for these patients were 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 89,041 cancer patients with DVT were identified who accounted for 289,233 inpatient hospital encounters. These patients comprised the study cohort. Of the total 24,470 (27.4%) patients who underwent IVC filter placement, 85.3% (20,875) underwent IVC filter placement within 30 days of initial DVT diagnosis. IVC filter patients had higher rates of bleeding risk factors including intracranial hemorrhage (2.6% vs 1.6% P < 0.001), lower GI bleed (8.1% vs 4.4%, P < 0.001), and hematuria (5.6% vs 3.4%, P < 0.001). In addition, IVC filter patients had higher rates of proximal DVT (53.9% vs 41.6%, P < 0.001) as well as the thrombosis risk factors of metastatic disease (47.7 vs 35.8%, P < 0.001) and coagulopathies (15.8% vs 12.3%, P < 0.001). After the initial DVT presentation, a total of 1,944 (2.2%) patients were diagnosed with PE. Adjusting for risk factors and anticoagulation use by a propensity matching algorithm, patients who received an IVC filter were noted to have a significantly improved PE-free survival at 6, 12, and 24 months relative to those who did not receive an IVC filter (96.6% vs 94.4%, 95.5% vs 92.3%, 94.0% vs 89.7%, P < 0.001). In cancer patients with DVT and bleeding risk factors, IVC filter placement is associated with an improved rate of PE-free survival.Tabled 1IVC filterNo IVC filterP ValuePatients (N)24,47065,571Age (median in years)7070NSGender (% female)50.750.6NSRace (%)NS White70.170.1 Black11.811.3 Hispanic14.114.1Intracranial hemorrhage (%)2.6%1.6%< 0.001Upper GI bleed (%)1.8%0.7%< 0.001Lower GI bleed (%)8.1%4.4%< 0.001Hematuria5.6%3.4%< 0.001Proximal DVT (%)53.9%41.6%< 0.001Metastatic disease (%)47.7%35.8%< 0.001Coagulopathy (%)15.8%12.3%< 0.001 Open table in a new tab