Risk factors for in-stent restenosis after vertebral ostium stenting.

PURPOSE: To determine whether vascular risk factors, underlying vessel diameter, and/or the type of stent affect restenosis rates for vertebral ostium stents.
METHODS: A single-center retrospective analysis was conducted of 44 patients (31 men; mean age 61 years, range 32-81) who underwent stenting of 48 ostial lesions in the vertebral arteries between 1999 and 2005. Only patients who underwent angiographic follow-up were included in the analysis. Cox regression analysis was utilized for risk factor association with binary restenosis (> or =50% versus <50%). Stent types and stent categories were compared for differences in binary restenosis rates and lumen gain at follow-up angiography.
RESULTS: Twenty-three (48%) of 48 lesions had > or =50% stenosis at a mean follow-up of 7.7 months. Cigarette smoking was associated with higher binary restenosis rates (p=0.025), while hypertension, diabetes, hyperlipidemia, history of neck radiation, and known coronary artery and/or peripheral vascular disease were not. Reduced binary restenosis rates and improved lumen gain were seen in cobalt chromium balloon-expandable stents compared to non-cobalt chromium stents (p=0.002 and p=0.002, respectively), stainless steel balloon-expandable stents (p=0.005 and p=0.005), and the S670 stent (p=0.069 and p=0.069). The size of stent used was not associated with risk of restenosis (p=0.756).
CONCLUSIONS: Cobalt chromium stents were associated with reduced restenosis, while smoking was associated with increased restenosis risk.