Intravascular ultrasound comparison of small coronary lesions between novel guidewire-based sirolimus-eluting stents and conventional sirolimus-eluting stents

BACKGROUND: The Sparrow stent system (Biosensors International) consists of a self-expanding, ultra-thin nitinol stent mounted within a 0.014 guidewire designed for small or tortuous coronary lesions. We compared the intravascular ultrasound (IVUS) findings between the novel self-expanding sirolimus-eluting stent (Sparrow-SES) and a conventional balloon-expandable sirolimus-eluting stent (Cypher-SES) in patients with small coronary disease. METHODS: We examined 14 lesions treated with the Sparrow-SES from CARE II, compared with 22 small vessel lesions treated with Cypher-SES. IVUS examination was performed post-procedure and 8 months later. Volumetric data were standardized by length as volume index (VI; mm(3)/mm). RESULTS: While baseline stent VI trended smaller in Sparrow-SES, follow-up stent VI became similar between the 2 groups due to a significant increase of stent VI in self-expanding Sparrow-SES during the follow-up period. At 8 months, Sparrow-SES showed greater neointima than Cypher-SES (0.8 +/- 0.6 mm(3)/mm vs 0.2 +/- 0.2 mm(3)/mm; P