To evaluate the patency of sirolimus-eluting stents (SES) compared to bare-metal stents (BMS) in the treatment of atherosclerotic renal artery stenosis (RAS).

Between November 2001 to June 2003, 105 consecutive symptomatic patients (53 men; mean age 65.7 years) with RAS were treated with either a bare-metal (n=52) or a drug-eluting (n=53) low-profile Palmaz-Genesis peripheral stent at 11 centers in a prospective nonrandomized trial. The primary endpoint was the angiographic result at 6 months measured with quantitative vessel analysis by an independent core laboratory. Secondary endpoints were technical and procedural success, clinical patency [no target lesion revascularization (TLR)], blood pressure and antihypertensive drug use, worsening of renal function, and no major adverse events at 1, 6, 12, and 24 months.

At 6 months, the overall in-stent diameter stenosis for BMS was 23.9%±22.9% versus 18.7%±15.6% for SES (p=0.39). The binary restenosis rate was 6.7% for SES versus 14.6% for the BMS (p=0.30). After 6 months and 1 year, TLR rate was 7.7% and 11.5%, respectively, in the BMS group versus 1.9% at both time points in the SES group (p=0.21). This rate remained stable up to the 2-year follow-up but did not reach significance due to the small sample. Even as early as 6 months, both types of stents significantly improved blood pressure and reduced antihypertensive medication compared to baseline (p<0.01). After 6 months, renal function worsened in 4.6% of the BMS patients and in 6.9% of the SES group. The rate of major adverse events was 23.7% for the BMS group and 26.8% for the SES at 2 years (p=0.80).

The angiographic outcome at 6 months did not show a significant difference between BMS and SES. Renal artery stenting with both stents significantly improved blood pressure. Future studies with a larger patient population and longer angiographic follow-up are warranted to determine if there is a significant benefit of drug-eluting stents in treating ostial renal artery stenosis.