Contemporary rates of inferior vena cava filter thrombosis and risk factors

Objective: Inferior vena cava (IVC) thrombosis is an uncommon complication associated with IVC filters (IVCFs), with studies reporting rates ranging from 1% to 31%. Few observational studies have described the risk factors associated with IVCF thrombosis, despite the significant clinical sequelae such as post-thrombotic syndrome, venous claudication, and venous ulceration. To better describe IVCF thrombosis and the risk factors, data were queried from Vascular Quality Initiative (VQI) participating centers. Methods: IVCF data were obtained from the international VQI database from 2013 to 2019. The patients included in the present analysis had 2 years of follow-up data available. The baseline demographics, medical comorbidities, medication, and procedural, anatomic, and postoperative variables were assessed using Kaplan-Meier survival curves with log-rank tests, Student's t tests, or Mann-Whitney U tests for IVCF thrombosis at 2 years. Cox regression analyses were used to identify independent predictors of IVCF thrombosis. A subgroup analysis of those who had presented with venous thromboembolism (VTE) was also performed. Results: A total of 62 U.S. and Canadian VQI-participating centers included 12,874 cases of IVCF placement. Of the 5780 cases with 2 years of follow-up available, 78 (1.3%) had developed IVCF thrombosis. Those who had experienced IVCF thrombosis had had significantly lower rates of diabetes, coronary artery disease, preoperative antiplatelet medications, preoperative statin use, and lower rates of discharge and follow-up antiplatelet medications. On univariable analysis, the cases of IVCF thrombosis also had higher rates of pulmonary embolism and VTE on admission, internal jugular venous access (vs femoral vein access), temporary IVCF use, follow-up anticoagulation, follow-up IVCF complication, follow-up access site thrombosis, and rates of new or propagated deep vein thrombosis at follow-up, and longer postoperative hospital stays. Multivariable analysis demonstrated that the independent predictors of IVCF thrombosis included new or propagated deep vein thrombosis at follow-up (hazard ratio [HR], 16.3; 95% confident interval [CI], 9.8-27.3; P < .001), no antiplatelet therapy at follow-up (HR, 4.8; 95% CI, 1.9-12.5; P = .001), internal jugular venous access (HR, 2.2; 95% CI, 1.4-3.5; P = .001), the presence of VTE on admission (HR, 2.7; 95% CI, 1.4-5.1; P = .002), and temporary IVCF placement (HR, 2.5; 95% CI, 1.1-5.6; P = .031). In an analysis of the subgroup of patients with VTE on admission, similar predictive factors were identified in a multivariable model. Massive pulmonary embolism was also predictive of IVCF thrombosis in this subgroup. Conclusions: The rate of IVCF thrombosis remained low in a contemporary international database. The results from the present study of >5000 patients with IVCFs suggest that antiplatelet therapy should be administered after IVCF placement to decreased the risk of IVCF thrombosis.