The placement of an inferior vena cava filter reduced the rate of pulmonary embolism (PE) in patients with deep venous thrombosis (DVT) and cancer, according to study results published in JAMA Network Open.

This population-based cohort study included encounter-level data from the (HCUP) databases. The analysis included a total of 88,585 patients (median age, 71.0 years) with malignant neoplasms and a diagnosis of acute lower extremity DVT from state inpatient databases from California (2005-2011) and Florida (2005-2014) who were enrolled in the HCUP.

Investigators examined all hospital visits for these patients to determine whether or not an IVC filter was placed. The primary outcome was the development of new PE following the initial DVT diagnosis. Additionally, the rates of new DVT as well as in-hospital mortality were examined.

A total of 33,740 (38.1%) patients in this study underwent placement of an IVC filter. The placement of a filter was significantly associated with several clinical risk factors, including upper gastrointestinal bleeding (odds ratio [OR], 1.32; 95% CI, 1.29-1.37), intracranial hemorrhage (OR, 1.21; 95% CI, 1.19-1.24), and coagulopathy (OR, 1.09; 95% CI, 1.08-1.10).


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Approximately 5.1% (n=4492) developed a new PE following their initial DVT diagnosis. In a time-variable analysis that used Cox proportional hazards regression, the investigators found a significant improvement in PE-free survival in patients who underwent placement of an IVC filter vs patients who did not (hazard ratio, 0.69; 95% CI, 0.64-0.75; P <.001).

Patients who received an IVC filter had worse overall in-hospital mortality vs patients who did not receive an IVC filter, which the investigators suggested likely reflects the poorer health status of those who underwent filter placement.

Additionally, a lower percentage of new DVT diagnoses were found in patients who received IVC filters compared with patients who did not undergo IVC filter placement in a propensity-score matching analysis (18.7% vs 22.1%, respectively; P <.001).

Placement of the IVC filter was associated with a significant reduction in the development of new DVT in patients who presented with pancreaticobiliary cancers (17.7% vs 22.0%; P <.001), lung cancers (18.0% vs 21.4%; P <.001), gastrointestinal tract cancers (17.0% vs 20.3%; P <.001), and prostate cancers (20.2% vs 23.1%; P =.01).

Study limitations included the reliance on database data and International Classification of Diseases, Ninth Revision codes for diagnoses as well as the inclusion of only encounter-level data and the exclusion of any out-of-hospital events.

The researchers concluded that “[t]hese data suggest that IVC filter use in patients with cancer is of potential benefit in appropriately selected patients,” but additional studies are needed to determine “the appropriate use of these devices.”

Reference

Balabhadra S, Kuban JD, Lee S, et al. Association of inferior vena cava filter placement with rates of pulmonary embolism in patients with cancer and acute lower extremity deep venous thrombosis [published online July 23, 2020]. JAMA Netw Open. doi:10.1001/jamanetworkopen.2020.11079