Closed-loop protocol for inferior vena cava filter management significantly improves retrieval: a competing-risk...

Inferior vena cava (IVC) filters are indicated only in acute venous thromboembolism (VTE) with an absolute contraindication to anticoagulation and should be retrieved once anticoagulation can be resumed. However, real-world retrieval rates remain low and highly variable. The objective is to assess whether implementing an institutional protocol improved appropriateness of IVC-filter placement and retrieval rates at 90 and 180 days, and to evaluate safety outcomes. Retrospective pre-post single-center study including adults who received an IVC filter between January 2015 and July 2025. Co-primary outcomes were appropriateness at placement (acute VTE ≤ 30 days plus absolute contraindication to anticoagulation) and retrieval, evaluated at 90 and 180 days using Fine-Gray competing-risk models. Among 234 patients (pre n = 182; post n = 52), cancer prevalence was similar (40.1% vs 38.5%). Appropriateness increased from 74.7% to 88.5% (risk ratio 1.18, 95% CI 1.04-1.35; p = 0.036). Retrieval improved at day 90 (41.2% → 65.4%, p = 0.020) and at day 180 (41.8% → 73.1%, p < 0.001). In Fine-Gray models, the post-protocol period was associated with a higher cumulative incidence of retrieval (adjusted sub-HR 1.68 [1.16-2.43] at 90 days; 1.92 [1.39-2.66] at 180 days), consistent with cause-specific Cox estimates. Procedure-related complications did not increase. Although overall mortality was unchanged, retrieval was independently associated with lower 180 days (adjusted HR 0.20 [0.08-0.48]). Implementing a closed-loop, guideline-aligned protocol improved appropriateness and substantially increased IVC-filter retrieval without compromising safety. Older age and active cancer remained barriers to retrieval, highlighting priority groups for targeted follow-up strategies.