PROOF trial: protection from pulmonary embolism with the OptEase filter

A postmarketing surveillance registry was conducted to monitor the safety and effectiveness of the OptEase vena cava filter when used as a permanent filter.

This study was a nonrandomized, multicenter prospective trial with all patients receiving the OptEase vena cava filter for the prevention of pulmonary embolism (PE). A total of 11 clinical sites in the United States enrolled patients. A 1-month postimplantation follow-up examination was performed to determine potential filter migration and the presence of symptomatic thrombosis of the inferior vena cava (IVC) or lower extremities. At 6-month postimplantation follow-up, patients were again assessed for the safety and stability of the filter and any clinical evidence of symptomatic thrombosis.

One hundred fifty patients were enrolled in this study. Fifty-five patients (36.6%) were unable to complete all of the necessary follow-up at 6 months. At 1 month, filter migration and filter-related symptomatic deep vein thrombosis was observed in one patient each (0.9% and 0.8%, respectively). At 6 months, no new cases of filter migration or filter-related symptomatic thrombosis were observed. Filter tilting (> or = 15 degrees off the IVC axis) was observed in one patient at baseline (0.7%), four patients at 1-month follow-up (3.6%), and three patients (11.4%) at 6-month follow-up. Incidental findings on follow-up radiographs included filter fracture in two patients (1.8%) at 1 month and in one additional patient (4.3%) at 6 months. There were no clinical sequelae associated with the filter fracture.

The co-primary endpoints of filter migration and symptomatic thrombus formation at 1 month had an observed frequency of 0.9% and 0.8%, respectively. These co-primary endpoints were stable and unchanged at 6 months.