Canadian Sirolimus-Eluting Stent in Coronary Lesions - C-SIRIUS
The goal of the Canadian Sirolimus-Eluting Stent in Coronary Lesions (C-SIRIUS) trial was to evaluate the efficacy of the sirolimus-eluting stent with a bare stent.
Use of the sirolimus-eluting stent will result in larger minimal lumen diameters (MLDs) at eight-month angiographic follow-up compared with use of a bare stent.
Patients Enrolled: 100
Mean Follow Up: 8-month angiographic; 5-year clinical (9-month data currently available)
Mean Patient Age: Mean age 60 years
Single de novo coronary lesion, stenosis >50% and <100%, stable or unstable angina or documented silent ischemia, lesion length 15-32 mm, and vessel diameter 2.5-3.0 mm by visual estimate.
MI within 24 hours, unprotected left main disease, ostial lesion, angiographic thrombus, pretreatment with devices other than balloon, left ventricular ejection fraction ≤25%, impaired renal function, and allergy to acetyl salicylic acid (ASA) or clopidogrel.
In-stent MLD at eight-month angiographic follow-up.
Nine-month: MACE (death/MI/emergent CABG/TLR), TLR, target vessel revascularization, target vessel failure.
Eight-month angiographic: in-lesion MLD, in-stent and in-lesion late loss, in-stent and in-lesion restenosis.
Patients with a single de novo coronary lesion were randomized to a sirolimus-eluting stent (n=50) or a bare stent (n=50). One or two stents were to be used in all patients.
Glycoprotein IIb/IIIa inhibitor was used in 48% of patients in the control arm and 58% of patients in the sirolimus arm (p=0.42). All patients received clopidogrel for two months.
Mean baseline lesion lengths were similar between the arms (12.6 mm control arm vs. 14.5 mm sirolimus arm, p=0.11) as were reference vessel diameters (2.62 mm control arm vs. 2.65 mm sirolimus arm, p=NS). The primary end point of in-stent MLD was larger in the sirolimus arm versus control (2.46 mm vs. 1.49 mm, p<0.001). In-stent late loss was smaller in the sirolimus arm (0.12 vs. 1.02 mm, p<0.001), and presence of binary restenosis >50% was less frequent (0% vs. 45.5%, p<0.001).
Similar results were seen with the in-lesion segment MLD: 2.15 mm versus 1.39 mm, p<0.001; late loss 0.12 mm versus 0.79 mm, p<0.001; and restenosis 2.3% versus 52.3%, p<0.001. Major adverse cardiac events (MACE) at nine months occurred less frequently in the sirolimus arm (4% vs. 18%, p=0.05), driven almost entirely by a reduction in target lesion revascularization (TLR; 4% vs. 18%, p=0.05). There were no deaths or Q wave myocardial infarctions (MIs) in either arm, and there was no difference in non-Q wave MI (n=2 in the bare stent arm vs. n=1 in the sirolimus arm, p=NS). One patient in each group had stent thrombosis.
Among patients undergoing percutaneous coronary intervention (PCI) for de novo coronary lesions, use of a sirolimus-coated stent was associated with larger in-stent MLDs and reduced restenosis at eight-month angiographic follow-up. Additionally, the nine-month MACE was lower in the sirolimus arm, although the reduction was driven entirely by TLR, with no deaths or Q wave MIs in either arm.
Patients enrolled in the C-SIRIUS trial had longer lesions in smaller vessels than the RAVEL trial, which reported similar angiographic and clinical findings, suggesting similar benefit with a sirolimus-eluting stent in more difficult lesions. Patients will be followed for up to five years for clinical events. These long-term data will be important in determining if the need for repeat revascularization is simply delayed in the sirolimus arm or not required, as well as determining if use of the eluting stent will result in a clinical reduction in death or MI, as too few events occurred by nine months to draw conclusions regarding death and MI.
Schampaert E, et al. 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). J Am Coll Cardiol 2004;43:1110-5.
Presented at Late-Breaking Clinical Trials, ACC 2003.
Keywords: Coronary Artery Disease, Myocardial Infarction, Follow-Up Studies, Thrombosis, Drug-Eluting Stents, Constriction, Pathologic, Sirolimus, Percutaneous Coronary Intervention
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