Age shapes long-term outcomes after multi-arterial CABG strategies

A late-breaking study drawing on more than 15 years of national outcomes data from the STS Adult Cardiac Surgery Database (ACSD) suggests that the two most commonly used multi-arterial coronary artery bypass grafting (CABG) strategies-bilateral internal thoracic artery (BITA) and single internal thoracic artery plus radial artery (SITA+RA)-offer comparable long-term survival overall, with important differences emerging by patient age.

The findings were presented as a late-breaking abstract at the 2026 Society of Thoracic Surgeons Annual Meeting, the world's premier forum for cardiothoracic surgery research and innovation.

The study, led by Thomas Schwann, MD, of Corewell Health William Beaumont University Hospital, represents the largest comparative effectiveness analysis to date of multi-arterial bypass grafting platforms in US practice, leveraging the depth, longitudinal follow-up, and real-world applicability of the ACSD.

Using ACSD data from 2008 to 2023, investigators analyzed longitudinal outcomes from more than 2.1 million CABG patients, ultimately identifying over 172,000 patients who underwent multi-arterial bypass grafting with either BITA, SITA+RA, or both BITA and RA. Long-term survival-extending up to 15 years-was assessed through linkage with the Centers for Disease Control and Prevention's National Death Index and Centers for Medicare & Medicaid Services claims databases, providing a level of follow-up rarely achievable in surgical studies.

After rigorous propensity-score matching and robust risk adjustment, the study found:

• Equivalent 15-year survival between BITA and SITA+RA strategies overall
• Improved survival with BITA in patients younger than 60 years
• Lower mortality with SITA+RA in patients aged 70 years and older
• Early (0–5 year) survival advantage for SITA+RA, with BITA trending toward benefit beyond 10 years
• Additional survival benefit when a third arterial conduit was used, regardless of strategy

Importantly, the study also documents a steady increase in multi-arterial CABG use across the US, rising from approximately 9% to more than 16% over the past decade, driven largely by growth in SITA+RA use.

These findings underscore the power of the STS National Database to answer clinically meaningful questions that randomized trials have struggled to resolve."

Dr. Thomas Schwann, lead author of the study

"In a contemporary, real-world U.S. population, we found that both BITA and SITA plus radial artery strategies provide excellent long-term outcomes," Dr. Schwann said. "Rather than a one-size-fits-all approach, our data suggest that patient age and life expectancy should play a central role in selecting the optimal multi-arterial bypass strategy.

Given the improved survival associated with additional arterial grafts beyond two, this should encourage and challenge surgeons to use as many arterial grafts as possible to optimize outcomes."

By leveraging the scale, granularity, and longitudinal linkage of the STS National Database, the study provides actionable insights for surgeons navigating conduit selection in multivessel coronary artery disease, particularly as multi-arterial grafting gains broader adoption.

The findings are expected to generate significant discussion at the 2026 STS Annual Meeting and may help inform future clinical guidelines, quality initiatives, and shared decision-making with patients.