Effectiveness of Inferior Vena Cava Filters in Patients With Stable and Unstable Pulmonary Embolism and Trends in Their Use.

Background: Trends in the use of inferior vena cava (IVC) filters in patients with pulmonary embolism (PE) who are stratified according to whether they are stable or unstable (in shock or ventilator dependent) may show where improvements of management could be made according to the best evidence that we now have.

Methods: This was a retrospective cohort study based on administrative data, 1999-2014, from the National (Nationwide) Inpatient Sample.

Results: In-hospital all-cause mortality in unstable patients who received an IVC filter was lower in each year of investigation and in all age groups. Mortality from 1999 to 2014 was 10,140 of 35,230 (28.8%) with an IVC filter compared with 54,018 of 116,642 (46.3%) without a filter (P <0.0001). In stable patients from 1999 to 2014, mortality with an IVC filter was 31,909 of 546,858 (5.8%) with an IVC filter compared with 220,443 of 3,367,783 (6.5%) without a filter (P <0.0001). In patients ages > 80 years, mortality in stable patients with an IVC filter was 7,438 of 114,457 (6.5%) with an IVC filter compared with 64,113 of 567,348 (11.3%) without an IVC filter (P <0.0001). The number of stable patients who received an IVC filter decreased from 2010 to 2014, but even in those years the largest number of IVC filters was inserted in stable patients, 194,502 of 212,611 (91.5%).

Conclusions: Mortality is markedly reduced in unstable patients who receive an IVC filter. Despite this, the proportion of unstable patients who receive an IVC filter is decreasing. The largest number of IVC filters continues to be inserted in stable patients, although there is no evidence of a clinically meaningful reduced mortality with IVC filters in stable patients unless age >80 years.