Optical Coherence Tomography May Improve Safety and Outcomes for Stenting Procedures in Heart Disease Patients Compared to Conventional Angiography
Results from a large-scale clinical trial result could increase usage of high resolution imaging for guiding interventional coronary procedures
Using optical coherence tomography (OCT) to guide stent implantation during percutaneous coronary intervention (PCI) may be safer and lead to better outcomes for heart disease patients than angiography-guided PCI alone, the most commonly used method.
These are the findings from the largest clinical trial of its kind comparing the two methods for this procedure. The “ILUMIEN IV: OPTIMAL PCI” study results were presented on Sunday, August 27, in a Hot Line session at the European Society of Cardiology Congress (ESC 2023) in Amsterdam, Netherlands, and published in The New England Journal of Medicine.
“Prior studies had demonstrated that intravascular imaging guidance of PCI procedures, particularly with intravascular ultrasound (IVUS), improves patient safety and clinical outcomes after coronary stent implantation. However, most of these trials were done outside the United States, and few tested PCI guided by OCT, which compared to IVUS offers superior resolution and accuracy,” says senior author Gregg W. Stone, MD. Dr. Stone is Director of Academic Affairs for the Mount Sinai Health System, Professor of Medicine (Cardiology), and Population Health Science and Policy, at the Icahn School of Medicine at Mount Sinai, and the study chairman of the ILUMIEN IV trial.
“The ILUMIEN IV trial demonstrated that OCT-guided PCI compared with angiography-guided PCI improves stent implantation results and the safety of the procedure, with less stent thrombosis, the most devastating complication of stenting,” Dr. Stone adds. “However, while there were numerically fewer cardiac deaths and myocardial infarctions (MIs) in the OCT group, the differences between groups in the primary composite outcome of cardiac death or MIs or repeat revascularization related to the treated vessel was not significant.”
Patients with coronary artery disease—plaque buildup inside the arteries that leads to chest pain, shortness of breath, and heart attack—often undergo PCI, a non-surgical procedure in which interventional cardiologists use a catheter to place stents in the blocked coronary arteries to restore blood flow. Interventional cardiologists most commonly use angiography to guide PCI, which involves a special dye (contrast material) and X-rays to see how blood flows through the heart arteries to highlight any blockages.
Angiography has limitations, making it difficult to determine the true artery size and the makeup of the plaque, and is suboptimal in identifying whether the stent is fully expanded post-PCI and other complications that affect the safety and effectiveness of the procedure. Intravascular ultrasound (IVUS) is another technique that provides a more accurate and specific picture of the coronary arteries. Even though studies have shown that IVUS-guided PCI is superior to angiography-guided PCI and reduces cardiovascular events, it is only used in roughly 15 to 20 percent of PCI cases in the United States, since images may be difficult to interpret.
An even newer technique is OCT, which uses light instead of sound to create images of the blockages. OCT images are much higher in resolution, more accurate, and more detailed compared to IVUS, and easier to interpret. However, as a newer technique, OCT is used in only 3 percent of PCI cases, partly because of a lack of study data—something this new trial aims to change.
The ILUMIEN IV: OPTIMAL PCI trial randomized 2,487 patients to OCT-guided PCI using a device manufactured by Abbott Vascular and angiography-guided PCI between May 2018 and December 2020. The study took place at 80 centers in 18 countries and patients did not know what type of guided procedure they received. Researchers evaluated the dimensions of the stented area post-PCI since re-narrowing of the stent over time can lead to repeat revascularization procedures.
Overall, patients in the OCT group had a substantially larger stent area compared to the angiography-guided group immediately after the procedure—an increase of .36mm2. OCT guidance also led to fewer procedural complications than angiography guidance. Researchers also looked at target lesion failure (TLF)—the combination of cardiac death, target-vessel myocardial infarction, or ischemia-driven target-vessel revascularization. Two years after the procedure, 88 patients in the OCT group had TLF compared to 99 in the angiography group, a difference that did not reach statistical significance.
The study went further and analyzed rates of stent thrombosis, one of the most severe complications of PCI. Within two years of PCI, six patients in the OCT group had stent thrombosis, compared to 17 in the angiography group, meaning that OCT reduced these instances by 65 percent. Additionally, 96 percent of patients who had a stent thrombosis in the trial died or had a subsequent myocardial infarction, emphasizing the importance of preventing these events.
“In summary, OCT guidance led to better implantation of the stent, a safer procedure, and a two-thirds reduction in stent thrombosis. The difference in TLF, while in favor of the OCT procedure, did not reach statistical significance in this trial, however, possibly due in part to the low rate of elective repeat procedures during the COVID-19 pandemic,” Dr. Stone said.
This study was funded by Abbott Vascular.
During the same hotline session at ESC 2023, Dr. Stone presented the results of an updated meta-analysis from the 20 trials of OCT-guided PCI and IVUS-guided PCI compared with angiography-guided-PCI, including ILUMIEN IV and one other new trial presented at the ESC. In total, 12,428 patients were enrolled in these studies, and results show that IVUS and OCT guidance reduced cardiac death by 46 percent, reduced target vessel myocardial infarction by 20 percent, and reduced target lesion revascularization by 29 percent, stent thrombosis by 52 percent, and overall target lesion failure by 31 percent compared with angiography guidance. The outcomes were similar for OCT-guided PCI and IVUS-guided PCI.
“These results emphasize the importance of physicians routinely using intravascular imaging with either OCT or IVUS to optimize stent outcomes and improve the long-term prognosis of their patients,” Dr. Stone said.
About the Mount Sinai Health System
Mount Sinai Health System is one of the largest academic medical systems in the New York metro area, with more than 43,000 employees working across eight hospitals, over 400 outpatient practices, nearly 300 labs, a school of nursing, and a leading school of medicine and graduate education. Mount Sinai advances health for all people, everywhere, by taking on the most complex health care challenges of our time — discovering and applying new scientific learning and knowledge; developing safer, more effective treatments; educating the next generation of medical leaders and innovators; and supporting local communities by delivering high-quality care to all who need it.
Through the integration of its hospitals, labs, and schools, Mount Sinai offers comprehensive health care solutions from birth through geriatrics, leveraging innovative approaches such as artificial intelligence and informatics while keeping patients’ medical and emotional needs at the center of all treatment. The Health System includes approximately 7,300 primary and specialty care physicians; 13 joint-venture outpatient surgery centers throughout the five boroughs of New York City, Westchester, Long Island, and Florida; and more than 30 affiliated community health centers. We are consistently ranked by U.S. News & World Report's Best Hospitals, receiving high "Honor Roll" status, and are highly ranked: No. 1 in Geriatrics and top 20 in Cardiology/Heart Surgery, Diabetes/Endocrinology, Gastroenterology/GI Surgery, Neurology/Neurosurgery, Orthopedics, Pulmonology/Lung Surgery, Rehabilitation, and Urology. New York Eye and Ear Infirmary of Mount Sinai is ranked No. 12 in Ophthalmology. U.S. News & World Report’s “Best Children’s Hospitals” ranks Mount Sinai Kravis Children's Hospital among the country’s best in several pediatric specialties.