Two of the most common strategies for multi-arterial coronary artery bypass graft (CABG)—using either the bilateral internal thoracic artery (BITA) or single internal thoracic artery plus radial artery (SITA+RA)—provide comparable long-term survival overall, with BITA offering a modest advantage among younger patients, compared to a small advantage for SITA+RA in older patients.
This is according to research presented during a late-breaking trial’s session at the Society of Thoracic Surgeons’ (STS) 2026 annual meeting (29–31 January, New Orleans, USA), drawing on more than 15 years of national outcomes data from the STS Adult Cardiac Surgery Database (ACSD).
The study, led by Thomas Schwann (Corewell Health William Beaumont University Hospital, Royal Oak, USA), 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, Schwann and his fellow investigators analysed 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 (CDC) National Death Index and Centers for Medicare & Medicaid Services (CMS) claims databases.
After propensity-score matching and 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 and lower mortality with SITA+RA in patients aged 70 years and older.
The researchers reported an early survival advantage between 0 and five years for SITA+RA, with BITA trending toward benefit beyond 10 years. An additional survival benefit was seen 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 USA, 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,” said Schwann, the lead author of the study.
“In a contemporary, real-world US population, we found that both BITA and SITA plus radial artery strategies provide excellent long-term outcomes,” 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 optimise outcomes.”
