Actionable Insights Newsletter

Translating research to power whole health

Issue 7    |    December 2023

Study finds medical device effective for treating life-threatening blood clots in the lung and leg

After the placement of the inferior vena cava filter, no fatal venous thromboembolisms occurred, and no pulmonary embolisms occurred in patients who received filters to prevent them.

Enterprise Analytics Core domain(s): Cardiometabolic

Summary

Background
Venous thromboembolism (VTE) is a condition that occurs when a blood clot forms in a vein, and can be the cause of serious conditions, such as pulmonary embolism (PE), a blood clot in the lung, and deep vein thrombosis (DVT), a blood clot in the leg. VTE occurs in nearly 400,000 people in the United States each year, and results in over 250,000 deaths annually.

The standard treatment for VTEs is called anti-coagulation, which is the use of a medicine to prevent blood from clotting, or to prevent existing clots from getting larger. Inferior vena cava (IVC) filters, small wire devices that are inserted into the inferior vena cava to prevent blood clots from traveling to the lungs, have become commonly used in people who have VTE but cannot tolerate anticoagulation medication.

The preventative use of IVC filters has increased steadily in settings where anticoagulation medication is thought to be inadequate or put a patient at a high bleeding risk, but there are limited data to support this increased use in patients without blood clots.

Objective
The Predicting Safety and Effectiveness in Inferior Vena Cava Filters (PRESERVE) study aimed to evaluate the safety and effectiveness of IVC filters in patients who needed PE prevention but could not take anticoagulation medicine.

Methods
PRESERVE was a prospective, open-label, non-randomized study of all commercially available IVC filters. The Society of Interventional Radiology and the Society for Vascular Surgery collaborated with Carelon Research to conduct the study at 54 sites in the United States between October 2015 and March 2019. During that time, filters were implanted in 1,421 patients, of which 1,019 patients had an existing clot in their leg, DVT, or a PE. Patients were followed for either one month after their IVC filter removal, or, if they had a permanent filter placed, up to 24-months after IVC filter placement.

Results

• After the placement of the IVC filter, 93 patients (6.5%) had a VTE, none of which were fatal, which is a slightly lower rate of VTE than described in previous studies.
  
• In the patients who received filters to prevent PEs, no PEs occurred. Researchers found that IVC filters were effective in helping to prevent PEs in patients who had a DVT but could not take anticoagulation medicines. A total of 632 (44.5%) of patients had their IVC filters removed as planned, most within 3 months of placement without complications and without the DVT or PE returning.
• The implantation of IVC filters was associated with few complications and a low incidence of PEs; seven out of a total of 1,421 adverse events were related to IVC filters, or about 0.5%.

Key takeaways