Postmarketing Surveillance of Inferior Vena Cava Filters Among US Medicare Beneficiaries: The SAFE-IVC Study

Abstract

Importance: Inferior vena cava filters (IVCFs) are commonly used to prevent pulmonary embolism in selected clinical scenarios, despite limited evidence to support their use. Current recommendations from professional societies and the US Food and Drug Administration endorse timely IVCF retrieval when clinically feasible. Current IVCF treatment patterns and outcomes remain poorly described.

Objectives: To evaluate temporal trends and practice patterns in IVCF insertion and retrieval among older US patients and report the incidence of periprocedural and long-term safety events of indwelling and retrieved IVCFs.

Design, setting, and participants: Prespecified, retrospective, observational cohort of Medicare Fee-for-Service (FFS) beneficiaries, leveraging 100% of samples of inpatient and outpatient claims data from January 1, 2013, to December 31, 2021.

Exposure: First-time IVCF insertion while insured by Medicare FFS.

Main outcomes and measures: The primary safety outcome was the composite of all-cause death, filter-related complications (eg, fracture, embolization), operating room visits following filter-related procedures, or new diagnosis of deep vein thrombosis (DVT). Events were considered periprocedural if they occurred within 30 days of IVCF insertion or retrieval and long-term if they occurred more than 30 days after.

Results: Among 270 866 patients with IVCFs placed during the study period (mean age, 75.1 years; 52.8% female), 64.9% were inserted for first-time venous thromboembolism (VTE), 26.3% for recurrent VTE, and 8.8% for VTE prophylaxis. Of these patients, 63.3% had major bleeds or trauma within 30 days of IVCF insertion. The volume of insertions decreased from 44 680 per year in 2013 to 19 501 per year in 2021. The cumulative incidence of retrieval was 15.3% at a median of 1.2 years and 16.8% at maximum follow-up of 9.0 years. Older age, more comorbidities, and Black race were associated with a decreased likelihood of retrieval, whereas placement at a large teaching hospital was associated with an increased likelihood of retrieval. The incidence of caval thrombosis and DVT among patients with nonretrieved IVCFs was 2.2% (95% CI, 2.1%-2.3%) and 9.2% (95% CI, 9.0%-9.3%), respectively. The majority (93.5%) of retrieval attempts were successful, with low incidence of 30-day complications (mortality, 0.7% [95% CI, 0.6%-0.8%]; filter-related complications, 1.4% [95% CI, 1.2%-1.5%]).

Conclusions and relevance: In this large, US real-world analysis, IVCF insertion declined, yet retrievals remained low. Strategies to increase timely retrieval are needed, as nonretrieved IVCFs may have long-term complications.

Figure 1.. Temporal Trends in Inferior Vena Cava Filter (IVCF) Insertions and Retrievals in the US

A, The incidence of IVCF procedures performed per 100 000 Medicare beneficiaries (y-axis) is reported for each quarter of the study period (x-axis). The number of procedures performed in a quarter was divided by the number of beneficiaries enrolled in Medicare Fee-for-Service in that quarter. B, For each quarter, the reported proportion’s denominator was the number of IVCFs placed in that quarter and the numerator was the number of those patients who had their IVCF retrieved at any subsequent time (through 2021). The incidence and proportion of retrieved IVCFs were not calculated for patients undergoing IVCF insertion in 2021 because there was insufficient follow-up time.

Figure 2.. Predictors of Inferior Vena Cava Filter (IVCF) Retrieval

The subdistribution hazard ratio (HR) for IVCF retrieval was estimated for a list of relevant clinical variables (taking into account the competing risk of death), where an HR greater than 1 indicated association with an increased likelihood of retrieval and an HR less than 1 indicated association with a decreased likelihood of retrieval. For clinical comorbidities, unless otherwise specified (in parentheses next to the predictor variable), the reference variable was the absence of the predictor variable of interest. For example, predictor variable anemia included all patients with a diagnosis of anemia (plus or minus other clinical comorbidities, when diagnosed), whereas the reference variable was patients who never received a diagnosis of anemia (but may have been diagnosed with other clinical comorbidities). VTE indicates venous thromboembolism. ^aComposite of diabetes, hyperlipidemia, and obesity. ^bComposite of acute myocardial infarction and ischemic heart disease. ^cComposite of hip and/or pelvic fracture and osteoporosis. ^dComposite of asthma and chronic obstructive pulmonary disease. ^eComposite of breast, colorectal, endometrial, lung, or prostate cancer, as well as leukemias and lymphomas.

Figure 3.. Cumulative Incidence Functions of Safety Events Among Patients With Indwelling Inferior Vena Cava Filters (IVCFs)

Cumulative incidence functions were used to estimate incidences of filter-related safety events annually and through maximum follow-up time for patients with indwelling IVCFs, accounting for the competing risk of death. For each line, the whiskers represent the 95% CI for each point estimate. DVT indicates deep vein thrombosis.