Study: OCT Offers Superior Resolution in Coronary Stent Implantation

Optical coherence tomography (OCT) provides safe and improved guidance for patients undergoing percutaneous coronary intervention to treat coronary artery disease, according to results from the ILLUMIEN III: OPTIMIZE PCI trial. The trial sought to determine whether a novel OCT-based stent sizing strategy would result in a comparable or superior minimal stent area (MSA) as achieved with former stent implant imaging techniques.
 
Researchers from NewYork-Presbyterian/Columbia University Medical Center presented the results as part of the late-breaking clinical trials session at the Transcatheter Cardiovascular Therapeutics (TCT) conference last weekend in Washington, D.C. The study has also been published in The Lancet and is available online.
 
“The trial shows that OCT-guided stent implantation provides equally large luminal dimensions as other techniques with enhanced accuracy and precision,” said Dr. Gregg W. Stone, director of Cardiovascular Research and Education at the Center for Interventional Vascular Therapy at NewYork-Presbyterian/Columbia University Irving Medical Center, professor of medicine at Columbia University Medical Center and study chairman of the trial. “Specifically, OCT allowed stenting to be performed with fewer dissections and malappositon, findings that have been associated with poor long-term results.”
 
Percutaneous coronary intervention (PCI) is a minimally invasive procedure that is primarily used to open a blocked coronary artery in order to restore blood flow to the heart. PCI is most commonly guided by angiography, which uses x-rays to view the blood vessels. However, the angiogram does not take into account details of the disease process of atherosclerosis, which happens in the wall of the artery. Angiography-guided PCI is imprecise, and is poor at identifying residual dissections, thrombus (blood clots) and plaque protrusion. Intravascular ultrasound (IVUS) can overcome these limitations by allowing for tomographic cross-sectional imaging of the vessel wall and has shown to reduce major adverse cardiovascular events. OCT is a newer imaging modality that provides higher resolution images than IVUS.
 
“We used a specific protocol of OCT which sized the coronary artery precisely, to see if it could provide advantages over angiography and be as good as or better than IVUS,” said Dr. Ziad A. Ali, associate director of translational medicine at the Center for Interventional Vascular Therapy at NewYork-Presbyterian/Columbia University Medical Center, assistant professor of medicine and the Louis V. Gerstner Scholar at Columbia University College of Physicians and Surgeons and principal investigator of the trial. “The superior resolution of OCT identified more dissections, malapposition and tissue protrusion compared with angiography or IVUS alone – while achieving improved stent expansion and procedural success when directly compared to angiography.”
 
OCT-guided PCI was non-inferior to IVUS for the primary study endpoint of acute procedural minimal stent area. 
The study examined outcomes of 450 patients at 29 hospitals in eight countries between May 2015 and April 2016. Patients were randomly assigned to receive either OCT-guided PCI, IVUS-guided PCI or angiography-guided PCI. It is the first study of its kind to compare all three modalities. All patients received clinical follow-up at 30 days and again at one year.
 
“ILUMIEN III: OPTIMIZE PCI is an important step toward our ultimate goal of improving patient outcomes with imaging during stenting.” said Dr. Stone. “These results have set the stage for a larger randomized trial, ILUMIEN IV, which is currently being planned to determine whether OCT-guidance results in superior clinical outcomes compared to angiography-guidance.”
 
Dr. Ali presented these findings at the TCT conference on Sunday, Oct. 30.
 
The study was funded by St. Jude Medical. See the paper for declaration of interests.