The Canadian study of the sirolimus-eluting stent in the treatment of patients with long de novo lesions in small native coronary arteries (C-SIRIUS).

OBJECTIVES: We assessed the safety and effectiveness of the sirolimus-eluting stent (SES) in treating single de novo long lesions in small native coronary arteries compared to an identical bare metal stent (BMS).

BACKGROUND: The SES was previously demonstrated to reduce restenosis significantly. However, patients with long lesions in small vessels have not been well studied and may define a group at very high risk.

METHODS: The Canadian Study of the Sirolimus-Eluting Stent in the Treatment of Patients With Long De Novo Lesions in Small Native Coronary Arteries (C-SIRIUS) was a multicenter, randomized, double-blind trial comparing SES versus identical BMS. The primary end point was in-stent minimal lumen diameter (MLD) at eight months. Secondary end points included angiographic restenosis at 8 months, target lesion revascularization (TLR), and major adverse cardiac events (MACE) at 270 days.

RESULTS: A total of 100 patients were enrolled at eight Canadian sites. The in-stent MLD at eight months was 2.46 +/- 0.37 mm in the SES compared with 1.49 +/- 0.75 mm in the BMS (a 65% increase, p < 0.001). Angiographic restenosis occurred in 1 of 44 SES patients (2.3%, with no in-stent restenosis) and in 23 of 44 BMS patients (52.3%, p < 0.001). At 270 days, there were two clinically driven TLRs in the SES (4%) and nine in the BMS (18%, p = 0.05). The Kaplan-Meier estimate of freedom from MACE at 270 days was 96.0% for SES patients and 81.7% for BMS patients (p = 0.029).

CONCLUSIONS: Patients with long lesions in small vessels are at very high risk of restenosis. In these patients, the SES dramatically reduces the risk of restenosis at eight months, translating into an excellent clinical outcome at nine months.