Clinical outcomes of inferior vena cava filter in complicated pulmonary embolism

Background: Previous observational studies suggest that inferior vena cava filter placement in pulmonary embolism patients complicated with congestive heart failure, mechanical ventilation, and shock may have a mortality benefit. We sought to analyze the survival benefits of inferior vena cava filter in pulmonary embolism patients complicated with acute myocardial infarction, acute respiratory failure, shock, or requiring treatment with thrombolytics. Methods: This retrospective observational study used hospital discharge data from the National Inpatient Sample Data (NIS). ICD-9-CM coding was used to identify complicated pulmonary embolism patients (N=254,465) in NIS from 2002 to 2014, including the subgroups of acute myocardial infarction, acute respiratory failure, shock, and thrombolytics. Inferior vena cava filter recipients were 1:1 propensity score-matched on age, sex, race, deep vein thrombosis, Elixhauser comorbidities, and other pulmonary embolism comorbidities (45 covariates) to non-inferior vena cava filter recipients in complicated pulmonary embolism patients and separately in each subgroup. Clinical outcomes were compared between the inferior vena cava filter group and the non-inferior vena cava filter group. Results: Mortality rate in complicated pulmonary embolism patients with inferior vena cava filter placement was lower (20.9% vs. 33%; NNT=8.28, 95% confidence interval (CI) 7.91-8.69, E-value=2.53) and in the subgroups; acute myocardial infarction (17.9% vs. 30.1%; NNT=8.19, 95% CI 7.52-8.92, E-value=2.76), acute respiratory failure (19.5% vs. 29.7%; NNT=9.76, 95% CI 8.67-11.16, E-value=2.38), shock (30.7% vs. 47.1%; NNT=6.08, 95% CI 5.73-6.47, E-value=2.43), and with the use of thrombolytics (7% vs. 12.9 %; NNT 17.1, 95% CI 14.88-20.12, E-value=3.01) (p<0.001 for all). Conclusion: Inferior vena cava filter placement in pulmonary embolism complicated with acute myocardial infarction, acute respiratory failure, shock, or requiring thrombolytic therapy was associated with reduced mortality.