Inferior Vena Cava Filters to Prevent Pulmonary Embolism: Systematic Review and Meta-Analysis

Abstract

Background: Inferior vena cava (IVC) filters are widely used for prevention of pulmonary embolism (PE). However, uncertainty persists about their efficacy and safety.

Objectives: The authors conducted a systematic review and meta-analysis of the published reports on the efficacy and safety of IVC filters.

Methods: The authors searched PubMed, the Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov through October 3, 2016, for randomized controlled trials (RCTs) or prospective controlled observational studies of IVC filters versus none in patients at risk of PE. Inverse variance fixed-effects models with odds ratio (OR) as the effect measure were used for primary analyses. Main outcomes included subsequent PE, PE-related mortality, all-cause mortality, and subsequent deep vein thrombosis (DVT).

Results: The authors' search retrieved 1,986 studies, of which 11 met criteria for inclusion (6 RCTs and 5 prospective observational studies). Quality of evidence for RCTs was low to moderate. Overall, patients receiving IVC filters had lower risk for subsequent PE (OR: 0.50; 95% confidence interval [CI]: 0.33 to 0.75); increased risk for DVT (OR: 1.70; 95% CI: 1.17 to 2.48); nonsignificantly lower PE-related mortality (OR: 0.51; 95% CI: 0.25 to 1.05); and no change in all-cause mortality (OR: 0.91; 95% CI: 0.70 to 1.19). Limiting the results to RCTs showed similar results. Findings were substantively similar across a wide range of sensitivity analyses.

Conclusions: Very few prospective controlled studies, with limited quality of evidence, exist regarding the efficacy and safety of IVC filters. Overall, filters appear to reduce the risk of subsequent PE, increase the risk for DVT, and have no significant effect on overall mortality.

Keywords: bleed; mortality; prevention; risk; venous thromboembolism.

FIGURE 1. PE and PE-Related Mortality

Pooled results from included studies indicated a lower rate of subsequent PE (A) and a nonsignificantly lower rate of PE-related mortality (B) in patients receiving IVC filters. CI = confidence interval; df = degree of freedom; DVT = deep vein thrombosis; IV = inverse variance; IVC = inferior vena cava; PE = pulmonary embolism; PREPIC = Prevention du Risque d'Embolie Pulmonaire par Interruption Cave; RCT = randomized controlled trial.

FIGURE 2. All-Cause Mortality

Pooled results indicated no significant difference in all-cause mortality between patients who received IVC filters versus controls. Abbreviations as in Figure 1.

FIGURE 3. Subsequent DVT

Pooled results showed increased risk of subsequent DVT in patients receiving IVC filters versus controls. Abbreviations as in Figure 1.

CENTRAL ILLUSTRATION. Use of IVC Filters Compared With Controls

In this review and analysis of studies of IVC filters versus none in patients at risk of PE, the results were limited by the small number of patients (total N = 4,204 patients, but fewer for some outcomes), methodological limitations with the included studies, and clinical heterogeneity across the studies. Summary results suggested that for every 100 patients, there would be 5 fewer subsequent PEs, 2 excess DVTs, and no change in all-cause mortality. The results appeared more favorable in limited scenarios that resembled guidelines indications, although no randomized trials existed. DVT = deep vein thrombosis; IVC = inferior vena cava; PE = pulmonary embolism.