Rationale and study design of the OISTER trial: optical coherence tomography evaluation of stent struts re-endothelialization in patients with non-ST-elevation acute coronary syndromes--a comparison of the intrEpide tRapidil eluting stent vs. taxus drug-eluting stent implantation.

Drug-eluting stents (DES) have been designed to prevent restenosis, but long-term clinical outcome may be offset by an increased risk of stent thrombosis, which is associated with suboptimal stent implantation or delayed re-endothelialization. DES implantation has also been associated with local persistent endothelial dysfunction. Conversely, Trapidil is a potent anti-inflammatory, vasodilatator and antiproliferative drug and several studies have shown anti-restenotic effects, suggesting substantial clinical benefits through the use of Trapidil-eluting DES. This is a longitudinal, single-blind, double-arm, randomized multicenter study. Forty patients with non-ST-elevation acute coronary syndromes who present at the index procedure with multivessel coronary disease in the major epicardial coronary arteries will be enrolled. Patients should present a culprit lesion with stenosis 70% or more associated with another stenosis 70% or more in another coronary artery. Patients will be randomized in a 1: 1 fashion to receive either an Intrepide trapidil-eluting stent or a Taxus paclitaxel-eluting stent on the culprit lesion. After 90 days, the nonculprit lesion will be treated with the stent of the opposite randomization arm and optical coherence tomography (OCT) analysis of the index stented segment will be performed. Follow-up angiography, combined with vasomotor analysis of endothelial function by rapid atrial pacing, will be done at 12 months after the index procedure on both stents. To further characterize the status of the endothelium, serum measurement of vascular endothelial growth factor gradient between the aorta and 15 mm distal to the implanted stent will be performed at 12 months. The primary endpoint of the study is to compare stent struts re-endothelialization at 90 days by OCT. The secondary endpoint is to compare angiographic outcome and coronary endothelial function 12 months after the index procedure and to compare clinical outcome at 1 and 2 years between trapidil-eluting DES versus paclitaxel-eluting DES. We hypothesize that the utilization of trapidil-eluting DES in the setting of acute coronary syndromes will be characterized by a greater early re-endothelialization associated with an antiproliferative effect offering a similar efficacy with a better safety profile compared with first-generation DES.