Sirolimus-Eluting Stent for the Treatment of In-Stent Restenosis - Sirolimus-Eluting Stent for the Treatment of In-Stent Restenosis
This was a single center angiographic and three-dimensional intravascular ultrasound (IVUS) study to evaluate the safety and efficacy of a sirolimus-eluting stent used to treat in-stent restenosis (ISR).
The aim of this pilot study was to determine the feasibility and safety of treating ISR with the slow-release sirolimus-eluting Bx Velocity stent.
Patients Enrolled: 25
Mean Follow Up: 1 year
Mean Patient Age: mean 56 yrs
Patients with ISR suitable for stenting with an 18 mm sirolimus-eluting Bx velocity stent
Previous intravascular radiation therapy to the target vessel; lesion >36 mm; saphenous vein graft lesion
Four and 12 month angiographic and IVUS assessment of neointimal hyperplasia
Four and 12 month minimum lumen diameter, binary restenosis, angiographic and volumetric late loss
Patients with ISR were successfully treated with the implantation of the slow-release (28 day drug release) sirolimus-eluting Bx-Velocity stent. 18 mm stents varying from 2.5-3.5 mm in diameter were used. After predilatation, stents were deployed with high-pressure (>14 atmospheres) postdilatation guided by IVUS to assure complete stent expansion and apposition. Debulking devices were not used, and predilatation was performed with a conventional balloon. The operator was allowed to implant up to 2 stents to cover the entire length of the lesion. Overlapping of the 2 adjacent stents was recommended.
Aspirin (325 mg/day, indefinitely) started at least 12 hours before the procedure and clopidogrel 300 mg immediately after stent implantation and 75 mg/day for the following 60 days.
25 consecutive patients were treated. 24% of patients were diabetic, and 20% of patients had recurrent ISR. The pattern of restenosis was focal (≤ 10 mm) in 32%, diffuse intrastent in 40%, and diffuse proliferative in 28% of the patients.
No patient had angina at 1 year and there were no major adverse cardiac events. No patients had restenosis at 4 months, and 1 patient (4%) had restenosis at 12 months. At 12 months, in-stent late loss was 0.36 mm and in-lesion late loss was 0.16 mm. In the 24 patients without restenosis in whom the IVUS catheter could be passed at 12 months, the mean lumen cross-sectional area was 7.06 mm-squared, and the mean percent obstruction (by volumetric IVUS) was 1.76%.
In this pilot study of patients with ISR amenable to treatment with one or two 18 mm sirolimus-eluting stents, favorable angiographic, IVUS, and clinical outcomes were observed, with only one patient (of 25) having recurrent restenosis, and with 12-month late loss of only 0.36 mm. Despite the fact that this was a small, single-center study, the initial results suggest that the sirolimus-eluting Bx-velocity stent may indeed be efficacious in treating ISR. Additionally reassuring was the absence of any cases of stent thrombosis despite the cessation of clopidogrel at 60 days. Whether these results are maintained at an even greater follow-up beyond one year remains to be determined.
Sousa JE, Costa MA, Abizaid A, et al. Sirolimus-Eluting Stent for the Treatment of In-Stent Restenosis: A Quantitative Coronary Angiography and Three-Dimensional Intravascular Ultrasound Study. Circulation 2003;107:24-27.
Keywords: Coronary Artery Disease, Follow-Up Studies, Platelet Aggregation Inhibitors, Thrombosis, Drug-Eluting Stents, Cross-Sectional Studies, Ticlopidine, Sirolimus, Diabetes Mellitus, Purinergic P2Y Receptor Antagonists, Stents
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