Objectives: A novel zotarolimus-eluting coronary stent system (ZoMaxx, Abbott Laboratories, Abbott Park, Illinois) was compared with a paclitaxel-eluting coronary stent (Taxus Express2) in a randomized trial of percutaneous intervention for de novo coronary artery stenosis. The primary end point was defined as noninferiority of in-segment late lumen loss after 9 months.
Background: The ZoMaxx stent system elutes 10 microg/mm zotarolimus using a phosphorylcholine polymer loaded onto a novel stainless steel stent platform containing a 0.0007-inch inner layer of tantalum.
Methods: Twenty-nine investigative sites in Europe, Australia, and New Zealand enrolled 401 patients, 396 of whom received a study stent.
Results: After 9 months, late lumen loss was significantly greater in the ZoMaxx group (in-stent 0.67 +/- 0.57 mm vs. 0.45 +/- 0.48 mm; p < 0.001; in-segment 0.43 +/- 0.60 mm vs. 0.25 +/- 0. 45 mm; p = 0.003), resulting in significantly higher rates of >50% angiographic restenosis (in-stent 12.9% vs. 5.7%; p = 0.03; in-segment 16.5% vs. 6.9%; p = 0.007). The upper bound of the 95% confidence interval on the difference in in-segment late lumen loss between the 2 treatment groups (0.27 mm) exceeded the 0.25 mm value pre-specified for noninferiority. There were no significant differences between ZoMaxx and Taxus-treated groups with respect to target lesion revascularization (8.0% vs. 4.1%; p = 0.14), major adverse cardiac events (12.6% vs. 9.6%; p = 0.43), or stent thrombosis (0.5% in both groups).
Conclusions: After 9 months, the ZoMaxx stent showed less neointimal inhibition than the Taxus stent, as shown by higher in-stent late loss and restenosis by qualitative coronary angiography.