Author + information
- Received December 1, 2008
- Accepted January 7, 2009
- Published online May 1, 2009.
- 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† and
- Miles Dalby, MD⁎,⁎ ()
- ↵⁎Reprint requests and correspondence:
Dr. Miles Dalby, Harefield University Hospital, Hill End Road, Harefield, Middlesex, UB9 6JH, United Kingdom
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)
This trial was supported through an unrestricted educational grant from Translumina, Germany.
Dr. Dalby has received honoraria from Translumina, Germany. Drs. Moore and Barlis contributed equally to this work and are joint first authors.
- Received December 1, 2008.
- Accepted January 7, 2009.
- American College of Cardiology Foundation