Intravascular ultrasound analysis of small vessel lesions treated with the sparrow coronary stent system: Results of the CARE II trial

Objectives The aim of this study was to evaluate the Sparrow sirolimus-eluting stent (Sparrow-SES) against the Sparrow bare-metal stent (Sparrow-BMS) and conventional balloon-expandable bare-metal stent (BMS: Driver/Micro-Driver^® stent, Medtronic Vascular, Santa Rosa, CA). Background The Sparrow^® stent (Biosensors International, Singapore) consists of a guide wire-based, self-expandable, ultra-thin nitinol stent. The performance of this device with sirolimus in a fully biodegradable polymer has not been determined. Methods A total of 74 patients were included in this intravascular ultrasound (IVUS) sub-study of the CARE II trial, which was a prospective, randomized, multicenter trial in the treatment of single de novo native coronary artery lesions in vessels ranging from 2.0 mm to 2.75 mm in diameter (Sparrow-SES: n = 31, Sparrow-BMS: n = 22, BMS: n = 21). Results Stent volume index (VI) was significantly increased 8-month later in Sparrow-SES and Sparrow-BMS, but not in BMS (4.0±1.0 to 4.6±1.0 mm³/mm, p<0.0001, 4.0±0.6 to 4.4±0.8 mm³/mm, p<0.05, and 5.2±1.0 to 5.1±0.9 mm³/mm, p=0.421, respectively). % neointimal obstruction in Sparrow-SES was significantly smaller than those in Sparrow-BMS and BMS at follow-up (17.6±9.4 vs. 36.2±13.8 and 39.9±11.1%, p<0.001). Sparrow-SES showed a mean 15% stent expansion and good suppression of neointimal proliferation, resulting in a significantly lower percentage of change in lumen VI during follow-up period (Sparrow-SES: -6.2±16.2%, Sparrow-BMS: -30.4±11.6%, BMS: -40.4±10.0%, p<0.001). Conclusions The self-expanding Sparrow-SES demonstrated chronic stent expansion, good suppression of neointimal proliferation and resulted in a more preserved lumen in stented small vessels compared with the Sparrow-BMS and conventional balloon expandable BMS. © 2013 Wiley Periodicals, Inc.