Evaluation of safety and efficacy of the S.M.A.R.T.® Flex Vascular Stent System (OPEN study)

Objectives The OPEN study evaluated the safety and efficacy of the S.M.A.R.T.® Flex Vascular Stent System in patients with femoropopliteal arterial disease. Background Long‐term data on endovascular treatments of femoropopliteal arterial disease are required to establish the repair durability. Methods The OPEN study was a multicenter, single‐arm, prospective study comparing primary safety and efficacy outcomes to performance goals (PG) developed for bare nitinol stents. Patients with symptoms due to a single, ≤180 mm length, de novo femoropopliteal arterial lesion with >70% stenosis were enrolled and followed for 36 months. Subjects with lesions ≤150 mm served as the initial comparison cohort for the PG (other cohorts were analyzed if the PG was met). Results 257 subjects with lesions ≤180 mm were enrolled. The mean lesion length was 71 ± 46 mm, and 52.5% had severe claudication. The primary safety endpoint (freedom from all‐cause death, index limb amputation, and target lesion revascularization [TLR] through 30 days) was met in 98.8% (96.5%, 99.6%) of subjects in the comparison cohort, meeting the PG (88.0%). The primary efficacy endpoint (comparison cohort vessel patency at 12 months) was 68.4% (61.1%, 74.8%), where the lower limit of the 95% confidence interval did not meet the 66.0% PG. Freedom from TLR in the per‐protocol cohort at 12‐, 24‐, 36‐month was 84.7%, 74.6%, and 72.8%, respectively. The 24‐month stent fracture rate was 4.3%, with no new fractures identified at 36 months. Conclusion The results show promising long‐term safety and effectiveness for the S.M.A.R.T.® Flex Vascular Stent System in patients with femoropopliteal arterial disease.