Impact of Stent Platform of Paclitaxel-Eluting Stents

BACKGROUND: The Taxus Express™ paclitaxel-eluting stent (Express-PES) and Taxus Liberte™ PES (Liberte-PES) have identical drugs, drug doses, and polymers, but different stent platforms. The Liberte-PES platform has thinner struts, specifically designed for more uniform drug elution. METHODS AND RESULTS: Fifty-four patients who underwent 6-month follow-up optical coherence tomography (OCT) after Express-PES (n=27) or Liberte-PES (n=27) implantation were enrolled. Longitudinal and circumferential uniformity of neointimal distribution was evaluated in 3-D by computing mean neointimal thickness (NIT) within 360 equally spaced radial sectors for every 1-mm cross-section. After stenting, intravascular ultrasound showed that Liberte-PES had a significantly smaller maximum angle between adjacent struts, with a tendency toward a lower incidence of % length of the segment with maximum angle >90° than Express-PES. Liberte-PES had a significantly thinner mean NIT than the Express-PES with comparable frequency of uncovered struts. Longitudinal and circumferential absolute variation of NIT expressed by standard deviation of NIT from each sector was significantly smaller for Liberte-PES than for Express-PES. Liberte-PES had a tendency toward a decreased incidence of thrombus and peri-strut low-intensity areas (findings suggestive of delayed arterial healing), compared to Express-PES. CONCLUSIONS: Stent design and thickness appeared to affect neointima suppression of PES. The stent platform of the Liberte-PES may offer greater and more homogeneous reduction of neointimal proliferation spatially across the full length of the PES.