A prospective randomised study using optical coherence tomography to assess endothelial coverage and neointimal proliferation at 6-months after implantation of a coronary everolimus-eluting stent compared with a bare metal stent postdilated with a paclitaxel-eluting balloon (OCTOPUS Trial): rationale, design and methods.
BACKGROUND
Safety concerns regarding use of drug-eluting stent systems (DES) are related mostly to late stent thrombosis, which is facilitated by incomplete stent endothelial coverage. Specific information about time course and amount of endothelial strut coverage of different DES is required, in order to further refine the concept of antiplatelet therapy after DES implantation. Optical coherence tomography (OCT) is emerging as a new gold standard for endovascular imaging of stents, atherosclerosis progression, vulnerable plaque, and neointimal proliferation. The aim of this study is a comparative evaluation using OCT of the XIENCE V everolimus-eluting stent (Abbot Vascular, Santa Clara, CA, USA) on one hand, and the bare metal stent Coroflex Blue postdilated with the paclitaxel-eluting balloon Sequent Please (both from B Braun Melsungen AG, Melsungen, Germany) on the other hand, with respect to endothelial coverage and neointimal proliferation.


METHODS
Eighty patients scheduled for elective percutaneous coronary intervention (PCI) of a native coronary stenosis suitable for DES implantation and OCT imaging are scheduled to be openly randomised 1:1 to either XIENCE or Coroflex Blue/Sequent Please. The study is conducted prospectively at a university high-volume PCI centre with OCT expertise. Angiographic follow-up and time-domain OCT imaging with motorised pull-back at 1 mm/s are planned six months after study stent implantation in all patients. OCT endpoints are: (1) endothelial coverage, expressed as % of struts without coverage and % of stent length containing non-covered struts, and respectively (2) neointimal proliferation, given as % neointimal volumetric proliferation within the whole stent and also as peak focal % neointimal area proliferation. The study is not powered for clinical endpoints, which are: subacute or late stent thrombosis and need for revascularisation of the stent segment. Given the high number of measurements (15 cross-section images / 1 mm stent length), OCT endpoints are likely to reach significance at the level p <0.05, if the drop-out rate in follow-up does not exceed 20%.


RESULTS
The study is currently on-going and its termination is scheduled for February 2010. (ClinicalTrials.gov identifier: NCT01056744).
1st Dept. of Medicine, Cardiology Division, University Hospital of Jena, Germany. tpoerner@googlemail.com
Tudor C
TC
Poerner
Sylvia
S
Otto
Johannes
J
Gassdorf
Florian
F
Janiak
Constance
C
Danzer
Markus
M
Ferrari
Hans R
HR
Figulla
D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects / Q000295:instrumentation*; D002317:Cardiovascular Agents / Q000008:administration & dosage*; D049109:Cell Proliferation / Q000187:drug effects*; D020099:Coated Materials, Biocompatible; D003324:Coronary Artery Disease / Q000628:therapy*; D023903:Coronary Restenosis / Q000209:etiology / Q000473:pathology / Q000517:prevention & control*; D016503:Drug Delivery Systems / Q000295:instrumentation*; D054855:Drug-Eluting Stents; D042783:Endothelial Cells / Q000187:drug effects* / Q000473:pathology; D000068338:Everolimus; D005858:Germany; D006801:Humans; D008670:Metals; D017239:Paclitaxel / Q000008:administration & dosage*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011474:Prosthesis Design; D012107:Research Design; D020123:Sirolimus / Q000008:administration & dosage / Q000031:analogs & derivatives*; D015607:Stents; D013997:Time Factors; D041623:Tomography, Optical Coherence; D016896:Treatment Outcome; D017539:Tunica Intima / Q000187:drug effects* / Q000473:pathology
D002317:Cardiovascular Agents; D020099:Coated Materials, Biocompatible; D008670:Metals; D000068338:Everolimus; D017239:Paclitaxel; D020123:Sirolimus