A Novel Bioresorbable Polymer Paclitaxel-Eluting Stent for the Treatment of Single and Multivessel Coronary Disease Primary Results of the COSTAR (Cobalt Chromium Stent With Antiproliferative for Restenosis) II Study

ObjectivesThe aim was to compare safety and effectiveness of the CoStar drug-eluting stent (DES) (Conor MedSystems, Menlo Park, California) with those of the Taxus DES (Boston Scientific, Maple Grove, Minnesota) in de novo single- and multivessel percutaneous coronary intervention (PCI).BackgroundPaclitaxel elution from a stent coated with biostable polymer (Taxus) reduces restenosis after PCI. The CoStar DES is a novel stent with laser-cut reservoirs containing bioresorable polymer loaded to elute 10 μg paclitaxel/30 days.MethodsPatients undergoing PCI for a single target lesion per vessel in up to 3 native epicardial vessels were randomly assigned 3:2 to CoStar or Taxus. Primary end point was 8-month major adverse cardiac events (MACE), defined as adjudicated death, myocardial infarction (MI), or clinically driven target vessel revascularization (TVR). Protocol-specified 9-month angiographic follow-up included 457 vessels in 286 patients.ResultsOf the 1,700 patients enrolled, 1,675 (98.5%) were evaluable (CoStar = 989; Taxus = 686), including 1,330 (79%) single-vessel and 345 (21%) multivessel PCI. The MACE rate at 8 months was 11.0% for CoStar versus 6.9% for Taxus (p < 0.005), including adjudicated death (0.5% vs. 0.7%, respectively), MI (3.4% vs. 2.4%, respectively), and TVR (8.1% vs. 4.3%, respectively). Per-vessel 9-month in-segment late loss was 0.49 mm with CoStar and 0.18 mm with Taxus (p < 0.0001). Findings were consistent across pre-specified subgroups.ConclusionsThe CoStar DES is not noninferior to the Taxus DES based on per-patient clinical and per-vessel angiographic analyses. The relative benefit of Taxus is primarily attributable to reduction in TVR. Follow-up to 9 months showed no apparent difference in death, MI, or stent thrombosis rates