Randomized comparison between polymer-free versus polymer-based paclitaxel-eluting stent: two-year final clinical results.

BACKGROUND Most drug-eluting stents currently in use are coated with a polymer carrying the drug that is released for several weeks. However, a durable polymer may provoke hypersensitive reaction, delayed artery healing, and eventually stent thrombosis. The aim of this study was to investigate the safety and efficacy of a polymer-free paclitaxel-eluting stent (PF-PES) versus a polymer-based PES (PB-PES). METHODS AND RESULTS Eligible patients undergoing percutaneous coronary intervention were randomized 1:1 to receive either PF-PES or PB-PES. The primary end point was late loss at 9 months. Intravascular ultrasound analysis at 9 months and final 2-year clinical follow-up were also performed. From October 2007 to April 2009, 164 patients were enrolled and randomized into 2 groups (PF-PES: n = 84; PB-PES: n = 80). Mean in-stent lumen loss was 0.90 ± 0.59 mm for PF-PES and 0.49 ± 0.52 mm for PB-PES (P < 0.001). Mean neointimal area by intravascular ultrasound was higher in PF-PES than in PB-PES (1.42 ± 1.09 versus 0.51 ± 0.61 mm(2); P < 0.001). At 2 years, a composite end point of all-cause death, any myocardial infarction, and target vessel revascularization occurred in 36.9% for PF-PES and 16.3% for PB-PES (P = 0.004), mainly driven by a higher rate of target vessel revascularization (PF-PES: 35.7%; PB-PES: 13.8%; P = 0.001). One late stent thrombosis was observed in PF-PES. CONCLUSIONS Compared with PB-PES, PF-PES was associated with increased neointimal proliferation and subsequent clinical restenosis. Polymer plays an essential role in the performance of drug-eluting stents. CLINICAL TRIAL REGISTRATION URL http://www.clinicaltrials.gov. Unique identifier: NCT01375855.