For patients with multivessel coronary artery disease, contemporary data analyses demonstrate that the optimal treatment is coronary artery bypass grafting (CABG), and that new downgraded recommendations for CABG could put patients at risk.
During the STS 59th Annual Meeting in January, researchers presented compelling findings, comparing outcomes for patients who underwent CABG versus those who opted for percutaneous coronary intervention (PCI).
“The findings of our study were very convincing,” said J. Hunter Mehaffey, MD, MSc, from the Department of Cardiovascular and Thoracic Surgery at West Virginia University. His team’s presentation, “Contemporary Artery Bypass Grafting versus Multivessel Percutaneous Coronary Intervention in 100,000 Matched Medicare Beneficiaries,” revealed that patients with blockages in multiple arteries who opt for CABG—rather than for PCI—are less likely to die from their condition, less likely to need additional surgery, and less likely to have a subsequent heart attack.
“The singular message to the public is that the optimal treatment for multivessel coronary artery disease—to improve not only long-term survival but also lower your risk of complications—is coronary artery bypass surgery.”
- J. Hunter Mehaffey, MD
The background and rationale for this research project started with the publication of the 2021 ACC/AHA/SCAI Guideline for Coronary Artery Revascularization. “The cardiac surgery world was really shocked, because the guidelines downgraded the indications for CABG from a class 1 recommendation to a class 2B,” Dr. Mehaffey explained.
Much of the decision to downgrade was based on the guideline committee’s goals to focus on the most recent data, to help ensure that they were capturing contemporary stent technology, Dr. Mehaffey explained. The guidelines therefore relied heavily on the multicenter ISCHEMIA trial, published by Maron et al in 2020.
“ISCHEMIA wasn’t a study that was designed to look at CABG versus medical therapy in terms of survival,” said Joseph F. Sabik III, MD, chair of the Department of Surgery at UH Cleveland Medical Center in Ohio. “It was really a study that was done to look at initial conservative strategy versus an initial invasive strategy.”
Dr. Mehaffey’s multidisciplinary team—including both surgeons and cardiologists—performed a statistical analysis of Medicare outcomes data in patients 65 and older from 2018 to 2020, including propensity score balancing to help ensure that the groups of patients who underwent stenting versus those who underwent bypass surgery were well matched in order to compare their outcomes.
The analysis demonstrated a significantly lower hospital mortality for the patients who underwent CABG compared to those who underwent PCI. Additionally, the researchers found a marked reduction in both 30-day and 3-year readmissions for myocardial infarction. CABG patients were also significantly less likely to need any additional stenting or intervention on their coronary arteries during those 3 years, and—most significantly—those who underwent CABG had a nearly 60% reduction in death at 3 years compared to those who had PCI.
“The singular message to the public is that the optimal treatment for multivessel coronary artery disease—to improve not only long-term survival but also lower your risk of complications—is coronary artery bypass surgery,” Dr. Mehaffey said.
Meanwhile, Dr. Sabik’s team analyzed the past 2 years’ outcomes in the STS National Database™, which captures nearly every adult cardiac surgical procedure in the United States. “We wanted to examine how representative ISCHEMIA is for patients undergoing surgery, to see if the results are applicable,” Dr. Sabik said.
They discovered that, based on the eligibility criteria for the ISCHEMIA trial, only about one-third of patients who underwent CABG would have been included in the study. A third would have been excluded because they had left main disease, and the other third would have met other exclusion criteria.
“ISCHEMIA wasn’t a study that was designed to look at CABG versus medical therapy in terms of survival. It was really a study that was done to look at initial conservative strategy versus an initial invasive strategy.”
- Joseph F. Sabik III, MD
Compared with that of the STS population, it turned out that patients who met ISCHEMIA criteria tended to have less severe disease. They didn’t have the same extent of coronary artery blockage or comorbid conditions. They tended to be younger, and they were less likely to have hypertension, diabetes, a previous stroke, peripheral vascular disease, or renal dysfunction, Dr. Sabik said. ISCHEMIA participants also were less likely to have had a myocardial infarction and more likely to have better left ventricular function.
“Though the authors of ISCHEMIA did their best to represent patients undergoing revascularization, the study wasn’t truly representative of patients with triple-vessel disease having surgery today,” concluded Dr. Sabik. “That’s why we don’t think it should have been used to downgrade coronary surgery recommendations. People are making decisions based on these guidelines, and it may not be in the best interest of patients.”
“This is not about surgery. It’s not about PCI, it’s not about medical therapy. It’s about making sure that patients get the right treatment, so they can have the best long-term outcomes.”
- Joseph F. Sabik III, MD
During the 2023 C. Walton Lillehei Lecture, Peter K. Smith, MD, outlined a series of narratives that can cloud a provider’s decision-making when choosing their approach to coronary artery disease. He illuminated the nuances of commonly cited trials such as SYNTAX and FAME, detailed the evolution of common percutaneous approaches, and explained how belief in the advantages of PCI becomes murkier when the arguments aren’t equivalent.
"There was exhaustive discussion of the age of the ‘CABG versus medical therapy’ evidence,” Dr. Smith said. “And then we entered the spin zone of indirect comparisons of ‘CABG versus medical therapy, CABG versus Stent X, Stent X versus Stent Y, Stent Y versus medical therapy—therefore CABG versus medical therapy.’ And, of course, ‘Those were all old stents and medical therapy is markedly improved now.’ This is what occurs when a core belief system is at risk.”
“We need to work at a local level with cardiology, with heart teams, in order to make the right decisions for patients,” urged Dr. Smith.
“This is not about surgery,” added Dr. Sabik. “It’s not about PCI, it’s not about medical therapy. It’s about making sure that patients get the right treatment, so they can have the best long-term outcomes.”
STS 2023 registrants can watch Dr. Mehaffey’s presentation, Dr. Smith’s Lillehei Lecture, and Dr. Sabik’s late-breaking session, “The ISCHEMIA Trial Does Not Reflect Patients Undergoing Coronary Surgery: An STS Cardiac Surgery Database Analysis,” as part of their free Annual Meeting Online access. Those who didn’t register can purchase Annual Meeting Online—with special discounts for STS Members—and Resident/Fellow Members can access it for free. Visit sts.org/AMonline.
