Sirolimus-eluting stent implantation in small coronary arteries: A three dimensional intravascular ultrasound study from the SIRIUS trial

Abstract

Aim To assess the efficacy of the sirolimus-eluting stent when implanted in smaller caliber vessels using three-dimensional intravascular ultrasound (IVUS) analysis. Methods One hundred and twenty-three patients (69 sirolimus-coated Bx Velocity and 54 control) who underwent successful three-dimensional IVUS at follow up comprised this IVUS substudy from the SIRIUS (SIRolImUS-coated Bx Velocity stent in the treatment of patients with de novo coronary artery lesions) population. To evaluate the impact of vessel size, 2 groups were created using QCA reference vessel diameter (RVD; large vessel group: RVD ≥ 2.75 mm and small vessel group: RVD < 2.75 mm). Results Sirolimus-eluting stents significantly reduced neointimal hyperplasia by the same relative magnitude within the stent in small vessels as well as in large vessels. Although sirolimus-eluting stents had favorable effects on lumen area at stent edges in larger vessels, the effect was less in smaller vessels, especially at the proximal edge. IVUS-detected adverse vessel response, such as late-acquired incomplete apposition, did not increase in smaller vessels even with relatively higher dose exposure. Conclusion Sirolimus-eluting stents showed inhibition of neointimal hyperplasia in small vessels compared to bare metal stents with no increase of vascular complications.