Inferior Vena Cava Filter Reduces DVT-Cancer Patient Risk of Pulmonary Embolism

Samyuktha Balabhadra, MD

An inferior vena cava (IVC) filter could significantly decrease mortality and pulmonary embolism risk for a cancer patient with deep vein thrombosis (DVT), according to new findings.

In a new population-based cohort analysis conducted by a team of Texas-based investigators, the two-fold increased risk of fatal pulmonary embolism prevalent in patients with cancer was diminished by the use of IVC filters in 88,000-plus patients in California and Florida over the span of an observed decade in care.

The findings benefit a field of oncology research limited in IVC filter device safety and efficacy data, despite the high prevalence of filter use in at-risk patients.

Namely, it evidences a commonly used treatment in patients with venous thromboembolism (VTE)—despite its association with potentially new DVT development or existing DVT propagation.

Investigators, led by Samyuktha Balabhadra, MD, of the Department of Radiology at the University of Texas Health McGovern School of Medicine, sought to understand the appropriate use of IVC filters in patients with cancer by evaluating associations between the devices and pulmonary embolism development among cancer patients with DVT.

“This knowledge gap in IVC filter utility and outcomes is even more pronounced for patients with cancer because very few studies have investigated this patient population, to our knowledge,” they wrote. “Defining the appropriate use of IVC filters in patients with cancer remains a substantially unmet clinical need.”

Their assessment included administrative data on 88,585 patients from state inpatient databases for California and Florida, ranging in years from 2005-2014.

Balabhadra and colleagues identified patients with cancer and acute lower extremity DVT through diagnostic and procedure codes. The team evaluate subsequent hospital visits among eligible patients for the placement of an IVC filter, new embolism development, new DVT development, and in-hospital mortality.

Pulmonary embolism-free survival was measured from initial DVT diagnosis date until the development of pulmonary embolism. In the event that a patient received a pulmonary embolism diagnosis at the same time as their initial DVT diagnosis, they were considered to not have developed a new pulmonary embolism.

Median patient age was 71 years old, with half (50.8%) being male. Patients were analyzed across 534,623 inpatient encounters, with a median follow-up time of 479 days.

Of the cohort, 33,740 patients (38.1%) underwent IVC filter placement—most (80.4%) occurring within 30 days of initial DVT diagnosis. Patient with comorbid risk factors including upper gastrointestinal bleeding, intracranial hemorrhage, and coagulopathy were at 32%, 21%, and 9% greater odds of receiving a filter, respectively.

A new pulmonary embolism developed in 5.1% of IVC filter-recipient patients after their initial DVT diagnosis.

Investigators observed a 31% improvement in pulmonary embolism-free survival among these patients than those who did not receive an IVC filter—even after propensity score matching and competing risk analysis (HR, 0.69; 95% CI, 0.64-0.75; P <.001).

IVC filter placement additionally reduced pulmonary embolism development risk among patients with very high-risk, high-risk, and low-risk malignant neoplasms.

Despite previous analyses, investigators did not observe an association between IVC filter placement and increased new DVT development risk, with account for patient anticoagulation use and imbalanced risk factors.

That said, Balabhadra and colleagues stressed the potential risk of IVC filter placement, as per communications from the US Food and Drug Administration (FDA) in 2014 and 2010 on their link to device migration, penetration, and embolization.

“The most common complication associated with IVC filters, however, is an increased incidence of DVT,” investigators wrote. “As the devices themselves represent foreign material within a blood vessel, they are to some extent thrombogenic and can lead to thrombus formation and propagation.”

Nonetheless, the team concluded that, when accounting for death as a competing risk and comorbidities by propensity score matching, IVC filter placement in cancer patients with DVT was linked to significantly reduced new pulmonary embolism.

“These data suggest that IVC filter use in patients with cancer is of potential benefit in appropriately selected patients, and that further investigations into the appropriate use of these devices is warranted,” they wrote.

The study, “Association of Inferior Vena Cava Filter Placement With Rates of Pulmonary Embolism in Patients With Cancer and Acute Lower Extremity Deep Venous Thrombosis,” was published online in JAMA Network Open.