Dedicated drug-eluting stents versus bare-metal stents for vertebral artery origin stenosis: a real-world single-center experience.

Background: In-stent restenosis (ISR) remains a major challenge following vertebral artery origin (VAO) stenting. Dedicated rapamycin-eluting vertebral artery stents were developed specifically for vertebral artery. This study aimed to compare the efficacy and safety of dedicated drug-eluting stents (DES) versus bare metal stents (BMS) in this anatomically complex lesion.

Methods: In this observational prospective, single-center cohort study, consecutive patients with symptomatic severe vertebral artery origin stenosis (VAOS) undergoing either dedicated DES or BMS implantation between January 2021 and December 2023 were enrolled. The primary efficacy endpoint was the 1-year ISR rate (> 50% luminal stenosis within or adjacent to the stent). The primary safety endpoint was 30-day stroke/death. Secondary endpoints included stroke occurring between 31 days and 1 year, symptomatic ISR within 1 year, all-cause mortality from 31 days to 1 year, stent fracture, and perioperative complications.

Results: A total of 217 patients were enrolled, including 150 dedicated DESs and 67 BMSs. Compared with the BMS group, the dedicated DES group showed Significantly lower 1-year ISR rates (14 [9.3%] vs. 25 [37.3%]; HR 0.22, 95% CI 0.11 - 0.45; p < 0.001), indicating a 75.1% relative risk reduction. No significant differences were observed in 30-day stroke/death (1 [0.7%] vs. 0 [0%]; p > 0.99) or 31-day to 1-year stroke (6 [4.0%] vs. 5 [7.5%]; OR 0.57, 95% CI 0.12 - 2.82; p = 0.49) between the two groups. Symptomatic ISR occurred exclusively in BMS group (2.6%, 1/39). Stent fracture rates were numerically higher with dedicated DES (13 [8.7%] vs 3 [4.5%], p = 0.60), with ISR occurring in 25.0% (4/16) of fractured versus 17.4% (35/201) of nonfractured stents. Mortality beyond 30 days was similar (1 [0.7%] vs 1 [1.5%], p > 0.99).

Conclusions: Rapamycin-eluting vertebral artery stents significantly reduced ISR rates compared to BMS in symptomatic severe VAOS, while maintaining comparable short- and mid-term safety. Stent fracture warrants further investigation as a potential modulator of ISR risk.