Serial angiography and intravascular ultrasound: results of the SISC Registry (Stents In Small Coronaries).

OBJECTIVES: The aim of this study was to evaluate the novel CardioMind Sparrow (CMS) stent (CardioMind, Inc., Sunnyvale, California) against the Multi-Link Pixel (MLP) stent (Guidant Corp., Santa Clara, California) for small vessel percutaneous coronary intervention (PCI). BACKGROUND: The CMS consists of a guidewire-based, self-expandable, ultra-thin nitinol stent with smaller profile and improved flexibility and deliverability. The performance of this novel device against a standard balloon-expandable stent for small vessel PCI has not been determined. METHODS: Twenty-one patients were treated with the CMS and compared with 30 patients treated with MLP. Only single de novo lesions <14 mm in length, in native vessels of 2.0 to 2.5 mm were included. The primary goal was the comparison of quantitative coronary angiography lumen loss and intravascular ultrasound intimal hyperplasia (IH) formation between groups at 6 months. RESULTS: Clinical characteristics were similar between groups. The CMS cohort had smaller vessels (2.20 +/- 0.20 mm vs. 2.43 +/- 0.16 mm, p < 0.0001) and shorter lesions (10.86 +/- 3.19 mm vs. 13.12 +/- 2.79 mm, p = 0.0091). Six-month late loss was significantly lower among CMS cohort (0.73 +/- 0.57 mm vs. 1.11 +/- 0.72 mm, p = 0.038). By intravascular ultrasound, 6-month IH volume was similar between groups (1.45 +/- 0.46 mm(3)/mm vs. 1.65 +/- 1.02 mm(3)/mm, p = 0.50). However, CMS presented a mean 13.39% expansion of its volumes, resulting in a significantly lower percentage of IH volumetric obstruction (31.94 +/- 8.19% vs. 39.90 +/- 4.72%, p = 0.0005). CONCLUSIONS: Despite producing similar amounts of IH volume, the self-expanding CMS stent presented chronic expansion of its volumes, better accommodating the neoformed tissue and resulting in significantly lower late loss and percent of IH volumetric obstruction in comparison with the MLP stent.