The effects of vena cava filters on case fatality rate are not clear, although they are used increasingly in patients with pulmonary embolism. The purpose of this investigation is to determine categories of patients with pulmonary embolism in whom vena cava filters reduce in-hospital case fatality rate.

In-hospital all-cause case fatality rate according to the use of vena cava filters was determined in patients with pulmonary embolism discharged from short-stay hospitals throughout the United States using data from the Nationwide Inpatient Sample.

In-hospital case fatality rate was marginally lower in stable patients who received a vena cava filter: 21,420 of 297,700 (7.2%) versus 135,240 of 1,712,800 (7.9%) (P<.0001). Filters did not improve in-hospital case fatality rate if deep venous thrombosis was diagnosed in stable patients. A few stable patients (1.4%) received thrombolytic therapy. Such patients who received a vena cava filter had a lower case fatality rate than those who did not: 550 of 8550 (6.4%) versus 2950 of 19,050 (15%) (P<.0001). Unstable patients who received thrombolytic therapy had a lower in-hospital case fatality rate with vena cava filters than those who did not: 505 of 6630 (7.6%) versus 2600 of 14,760 (18%) (P<.0001). Unstable patients who did not receive thrombolytic therapy also had a lower in-hospital case fatality rate with a vena cava filter: 4260 of 12,850 (33%) versus 19,560 of 38,000 (51%) (P<.0001).

At present, it seems prudent to consider a vena cava filter in patients with pulmonary embolism who are receiving thrombolytic therapy and in unstable patients who may not be candidates for thrombolytic therapy. Future prospective study is warranted to better define in which patients a filter is appropriate.