This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Moore, P. Articles by Dalby, M. Search for Related Content PubMed Articles by Moore, P. Articles by Dalby, M.

A Randomized Optical Coherence Tomography Study of Coronary Stent Strut Coverage and Luminal Protrusion With Rapamycin-Eluting Stents

Philip Moore, MD^_*, Peter Barlis, MD^_*, Jonathan Spiro, MD^_*, Gopal Ghimire, MD^_*, Michael Roughton, MSc^_*, Carlo Di Mario, MD^_*, William Wallis, MD^_*, Charles Ilsley, MD^_*, Andrew Mitchell, MD^_*, Mark Mason, MD^_*, Rajesh Kharbanda, MD^_*, Peter Vincent, BSc, Spencer Sherwin, PhD, Miles Dalby, MD^_*,_*

^_* Royal Brompton & Harefield NHS Trust, Middlesex, United Kingdom
Department of Aeronautics, Imperial College, London, United Kingdom

^_* Reprint requests and correspondence: Dr. Miles Dalby, Harefield University Hospital, Hill End Road, Harefield, Middlesex, UB9 6JH, United Kingdom (Email: m.dalby{at}rbht.nhs.uk).

Objectives: We used optical coherence tomography, which has a resolution of <20 µm, to analyze thin layers of neointima in rapamycin-eluting coronary stents.

Background: Lack of neointimal coverage has been implicated in the pathogenesis of drug-eluting coronary stent thrombosis. Angiography and intracoronary ultrasound lack the resolution to examine this.

Methods: We conducted a randomized trial in patients receiving polymer-coated rapamycin-eluting stents (Cypher, Cordis, Johnson & Johnson, Miami, Florida) and nonpolymer rapamycin-eluting stents (Yukon, Translumina, Hechingen, Germany) to examine neointimal thickness, stent strut coverage, and protrusion at 90 days. Twenty-four patients (n = 12 for each group) underwent stent deployment and invasive follow-up at 90 days with optical coherence tomography. The primary end point was binary stent strut coverage. Coprimary end points were neointimal thickness and stent strut luminal protrusion.

Results: No patient had angiographic restenosis. For polymer-coated and nonpolymer rapamycin-eluting stents, respectively, mean (SD), neointimal thickness was 77.2 (25.6) µm versus 191.2 (86.7) µm (p < 0.001). Binary stent strut coverage was 88.3% (11.8) versus 97.2% (6.1) (p = 0.030). Binary stent strut protrusion was 26.5% (17.5) versus 4.8% (8.6) (p = 0.001).

Conclusions: Mean neointimal thickness for the polymer-coated rapamycin-eluting stent was significantly less than the nonpolymer rapamycin-eluting stent but as a result coverage was not homogenous, with >10% of struts being uncovered. High-resolution imaging allowed development of the concept of the protrusion index, and >25% of struts protruded into the vessel lumen with the polymer-coated rapamycin-eluting stent compared with <5% with the nonpolymer rapamycin-eluting stent. These findings may have important implications for the risk of stent thrombosis and, therefore, future stent design. (An optical coherence tomography study to determine stent coverage in polymer coated versus bare metal rapamycin eluting stents. ORCA 1, from the Optimal Revascularization of the Coronary Arteries group; ISRCTN42475919)

Key Words: stents • optical coherence tomography • stent thrombosis

Abbreviations and Acronyms   BMS = bare-metal stent(s)   OCT = optical coherence tomography   3D = three-dimensional