Impact of Carbon Coating on the Restenosis Rate after Stenting of Atherosclerotic Renal Artery Stenosis

Abstract

Purpose:

To investigate the impact of carbofilm coating and low-profile rapid exchange stent devices on the restenosis rate after stent-angioplasty of atherosclerotic renal artery stenosis (RAS).

Methods:

During a 2-year period (7/2002-7/2004), 143 consecutive patients with 179 primary ostial atherosclerotic RAS ≥70% diameter stenosis were treated with stents selected at the discretion of the operator. Eighteen patients (32 lesions) treated with 9 different types of stents were excluded from the analysis, leaving 125 patients (69 men; mean age 67 years, range 42 to 90) with 147 lesions who received either a Radix carbofilm-coated stent in 78 (53%) lesions (68 [54%] patients) or a Palmaz Genesis bare stainless steel stent in 69 (47%) lesions (57 [46%] patients). The target vessel diameter ranged from 5 to 7 mm.

Results:

Baseline characteristics were similar in both groups except the mean stent diameter, which was larger in the bare stent cohort (6.4±0.7 versus 5.9±0.5 mm, p < 0.001). Primary success was 100% in both groups; the initial mean diameter stenosis was reduced from 79%±14% and 80%±14% in the coated versus bare stent groups to 3±5% and 2±6%, respectively. After a mean follow-up of 22±5 months, the restenosis rate was 6.4% for the coated stent and 5.8% for the bare stent (p=0.87). For the entire cohort, restenosis rates varied significantly (p < 0.05) according to stent diameter: 19% (5/26) for 5 mm, 4% (3/81) for 6 mm, and 2.5% (1/40) for 7 mm. In a binary logistic regression analysis including carbofilm coating, stent diameter, gender, diabetes, smoking status, and body mass index, stent diameter was the only independent predictor of restenosis (odds ratio 0.12, 95% CI 0.03 to 0.48 [p=0.003] for a 1-mm increase in vessel diameter).

Conclusions:

Using modern low-profile stent devices, carbofilm coating does not significantly reduce the restenosis rate compared to a bare metal stent. With contemporary stent devices, the restenosis rate has been decreasing compared to earlier reports in the literature.