Objective: To evaluate the performance of a biodegradable polymer based rapamycin-eluting coronary stent in a porcine model and demonstrate its safety and efficacy in the treatment of patients with de novo coronary stenosis.
Background: The indefinite presence of the polymer after the implantation of drug-eluting stents may initiate and sustain inflammation and contribute to the occurrence of late complications.
Methods: Seven study stents and 5 polymer-coated (control) stents were implanted in porcine carotid arteries. Histomorphometric analysis was performed 8 weeks after stent implantation. After establishing the safety of the stent in the animal model, a single-center, non-randomized study in patients with de novo coronary artery lesions was performed. Forty-nine stents were implanted in 43 patients. The 6-month clinical follow-up was 91% (39/43) and angiographic follow-up was 67% (29/43). The primary safety endpoint was the occurrence of 30-day major adverse cardiovascular events (MACE) and the principal efficacy endpoint was the 6-month angiographic late loss and binary restenosis rate.
Results: In the porcine model, the study stent showed acceptably low injury, inflammation and fibrin scores. There was a quantitative reduction in neointimal hyperplasia which was not statistically different from the control stent. However, in the first-in-man evaluation, there was significant suppression of intimal growth as evidenced by an angiographic late loss of 0.28 +/- 0.45 mm at 6 months. The restenosis rate was 10.3% (3/297). There was no death, stent thrombosis or myocardial infarction at 30 days or at 6 months. The 6-month target lesion revascularization rate was 3.47 percent; (1/29).
Conclusion: This preclinical and early clinical experience demonstrates the safety and efficacy of a novel biodegradable polymer-based rapamycin-eluting coronary stent.