Hybrid Sirolimus-eluting Versus Everolimus-eluting Stents for Total Coronary Occlusions

Overview

Percutaneous recanalization of total coronary occlusions (TCO) was historically hampered by high rates of restenosis and reocclusion. In the PRISON II and III trial we showed landmark reduction in restenosis with sirolimus-eluting stents (Cypher, Cordis Corporation) compared to conventional bare metal stents in TCO. In the PRISON III trial, we observed similar favourable results with second-generation zotarolimus-eluting stent (Resolute, Medtronic Inc.). Another drugs-eluting stent mounted with everolimus (Xience Prime, Abbott) also demonstrated favourable results in TCO. Recently, drug-eluting stents (DES) with bioresorbable polymer coatings were developed, to address safety concerns regarding the observation of very late stent thrombosis, due to hypersensitivity reactions, and chronic inflammation, on the durable polymer coating of DES. However, none of these DES with bioresorbable polymers were evaluated in patients with TCO. The PRISON IV trial is a prospective, randomized, single-blinded, multi-center trial, designed to evaluate the safety, efficacy, and angiographic outcome of hybrid sirolimus-eluting stents with bioresorbable polymers (ORSIRO, Biotronik Inc.) compared to everolimus-eluting stents with durable polymers (Xience Prime, Abbott) in patients with successfully recanalized TCOs.

A total of 330 patients are randomized to either hybrid sirolimus-eluting stent or everolimus-eluting stent after successful recanalization of TCO. Clinical follow-up at 1, 6, 12 months, 2, 3, 4, 5 year with angiographic follow-up at 9 months. In 60 patients a optical coherence tomography is performed during the 9 months follow-up angiography. Quantitative coronary and optical coherence tomography analysis is performed by two independent core laboratory. The primary end point is in-segment late luminal loss at 9 month angiographic follow-up. Secondary angiographic end points include the following; in-stent luminal loss, acute recoil, acute gain, net luminal gain, late loss index, minimal lumen diameter, percentage of diameter stenosis, in-stent and in-segment binary restenosis and reocclusions at 9 months angiographic follow-up. Secondary clinical endpoints include a composite of major adverse cardiac events (death, MI and clinically driven target lesion revascularization); clinically driven target vessel revascularisation (TVR), target vessel failure (cardiac death, MI, clinically driven TVR) and stent thrombosis up to 5 year clinical follow-up. Tertiary optical coherence tomography end points at 9 months follow-up are the following: Percentage of uncovered stent struts, percentage of malapposed stent struts, tissue strut thickness, absolute and percentage of intimal hyperplasia.