Randomized, double-blind, multicenter study of the polymer-based 17-beta estradiol-eluting stent for treatment of native coronary artery lesions: six-month results of the ETHOS I trial.

Objectives: The ETHOS I trial was the first in-human experience evaluating the safety and efficacy of two different release formulations of the 17-beta estradiol-eluting R-Stent versus uncoated control stents for the treatment of patients with single de novo native coronary lesions.

Background: Estrogens were reported to inhibit neointimal proliferation and to accelerate endothelial regeneration after coronary angioplasty and thus could be an ideal compound to deliver on a stent for the purpose of reducing in-stent restenosis.

Methods: Ninety-five patients were randomized to receive a slow-release (n = 32) or the moderate release (n = 31) formulations or the bare metal stent (n = 32). The primary end point was the 6-month percent in-stent volume obstruction by intravascular ultrasound (IVUS).

Results: Diabetes was present in 29.5% of patients; the mean reference vessel diameter was 2.90 mm; and the mean lesion length was 13.5 mm. Primary endpoint, 6-month percent in-stent volume obstruction by IVUS, did not differ significantly between the 3 groups (31% +/- 14%, 33% +/- 11%, and 31% +/- 14%, P = 0.83). Secondary endpoints also did not differ significantly between the groups including 6-month rates of in-lesion binary angiographic restenosis (13.3%, 14.3%, and 12.5%, P = 0.98), in-stent late loss (0.82 +/- 0.49 mm, 0.86 +/- 0.53 mm, and 0.84 +/- 0.46 mm, P = 0.97), target lesion revascularization (12.5%, 6.9%, and 6.5%, P = 0.64), and major adverse cardiac events (18.8%, 10.3%, and 6.5%, P = 0.31).

Conclusions: In this first-in-man randomized trial, the 17-beta estradiol-eluting R-Stent, in either slow- or moderate-release formulations, was well-tolerated, but showed no benefit for treatment of coronary lesions when compared to controls.