Strut Coverage and Vessel Wall Response to a New-Generation Paclitaxel-Eluting Stent With an Ultrathin Biodegradable Abluminal Polymer

Abstract

Background— Polymer-coated drug-eluting stents are effective in preventing restenosis but have been associated with delayed healing and incomplete strut coverage. It is unknown whether paclitaxel-eluting stents (PES) with minimal biodegradable abluminal coating enhances strut coverage while preventing neointimal hyperplasia. Using optical coherence tomography (OCT) as a primary imaging modality, we assessed the proportion of uncovered struts at 6-month follow-up in PES coated with durable versus ultrathin (<1 μm) biodegradable abluminal polymers. Methods and Results— In this pilot trial, 60 patients with de novo lesions (≤25 mm) in native coronary vessels were randomly assigned to receive either TAXUS Liberté PES or JACTAX PES, a Liberté stent with polymer deposited abluminally as microdots (JACTAX HD: 9.2 μg each of polymer and paclitaxel per 16-mm stent; JACTAX LD: 5 μg each). OCT follow-up occurred at 6 months with clinical follow-up through 1 year. The primary end point was percent uncovered struts by OCT. An independent core laboratory blinded to stent assignment analyzed images. The 6-month rate of uncovered struts per patient was 5.3±14.7% for TAXUS Liberté, 7.0±12.2% for JACTAX HD, and 4.6±7.3% for JACTAX LD ( P =0.81); percent malapposed struts was 1.4±4.4%, 0.8±1.9%, and 1.1±2.8%, respectively ( P =0.86). Strut-level intimal thickness was 0.20±0.10, 0.22±0.15, and 0.24±0.15 mm ( P =0.64); percent volume obstruction by OCT was 22.2±12.8, 22.5±16.2, and 25.8±15.2 ( P =0.69). There were no deaths, Q-wave myocardial infarctions, or stent thromboses through 1 year. Conclusions— JACTAX PES with an ultrathin microdot biodegradable abluminal polymer did not result in improved strut coverage at 6 months compared with TAXUS Liberté. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT00776204.