Large-Scale Study Compares CABG and PCI for Multivessel CAD in Medicare Patients in the United States

January 23, 2023—The Society of Thoracic Surgeons (STS) announced that a study demonstrating that for patients with multivessel coronary artery disease (CAD), those undergoing coronary artery bypass grafting (CABG) were less likely to die from their condition, less likely to need additional surgery, and less likely to experience a myocardial infarction than patients undergoing percutaneous coronary intervention (PCI).

The study was composed of > 100,000 patients with multivessel CAD, of whom 51,000 were treated with CABG and 52,000 were treated with PCI.

The results from the study, “Contemporary Artery Bypass Grafting versus Multivessel Percutaneous Coronary Intervention in 100,000 Matched Medicare Beneficiaries,” were presented at the STS 59th annual meeting held January 21-23 in San Diego, California.

The analysis was performed by a multidisciplinary team that included cardiac surgeons, cardiologists, and researchers at West Virginia University led by J. Hunter Mehaffey, MD. Dr. Mehaffey is with the Department of Cardiovascular and Thoracic Surgery at West Virginia University in Morgantown, West Virginia.

“The findings of our study were very convincing,” commented Dr. Mehaffey in the STS press release. “The singular message to the public is that the optimal treatment for multivessel CAD—to improve not only long-term survival but also lower your risk of complications—is coronary artery bypass surgery.”

In the STS press release, Dr. Mehaffey explained that the background and rationale for this study started with the publication of the 2021 American College of Cardiology/American Heart Association/Society for Cardiovascular Angiography & Interventions guideline for coronary artery revascularization, which was announced on December 9, 2021. The guideline by Jennifer S. Lawton, MD, et al is available online in Journal of the American College of Cardiology and Circulation.

Dr. Mehaffey noted, “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 continued, “Much of this decision to downgrade was based on the guideline committee’s goals to focus on the most recent data, to ensure that they were capturing contemporary stent technology, so they only evaluated studies published within the past 5 years. Therefore, these guidelines relied heavily on the recently publicized ISCHEMIA trial, which looked at medical therapy in CAD, comparing an initial invasive approach versus a conservative approach to patients who had stable CAD.”

As stated in the STS press release, the problem that arises when using ISCHEMIA (trial website: ischemiatrial.org; NCT01471522) to compare CABG to stenting is that the majority of patients in the ISCHEMIA trial were not representative of patients undergoing CABG in the United States. Therefore, the study did not fully represent the comparative benefits for patients who had multiple blockages in their coronary arteries.

Dr. Mehaffey’s team sought to conduct a large contemporary analysis that more fully represented this population, comparing patients undergoing CABG with those undergoing PCI with stenting. To ensure that the study included only the most contemporary technology, their longitudinal analysis captured outcomes over a 3-year period (2018-2020).

“We used one of the largest and most inclusive databases of patients hospitalized in the United States, including all patients over the age of 65 on Medicare,” explained Dr. Mehaffey in the STS press release. “We performed a very robust statistical analysis including propensity score balancing to help ensure that the groups of patients who underwent stenting versus those who underwent bypass surgery were well matched and well balanced in order to compare their outcomes.”

As summarized in the STS press release, the analysis demonstrated significantly lower hospital mortality for the patients who underwent CABG compared to those who underwent stenting. Additionally, the investigators 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 an approximately 60% reduction in death at 3 years compared to those who had stenting, reported STS.

“Regardless of your specialty, these data demonstrate the importance of assessing longitudinal outcomes to help ensure we’re making optimal treatment recommendations for our patients,” concluded Dr. Mehaffey in the STS press release.

Also at the STS annual meeting, the C. Walton Lillehei Lecture by Peter K. Smith, MD, “Treatment Selection for Coronary Artery Disease: The Collision of a Belief System with Evidence,” will be presented January 23 at 9:00 am PT, and Joseph F. Sabik III, MD, will present “The ISCHEMIA Study Does Not Reflect Patients Undergoing Coronary Surgery: An STS Adult Cardiac Surgery Database Analysis” on January 23 at 11:30 am PT.