NEW ORLEANS—January 31, 2026— A late-breaking study leveraging more than 1.5 million patient records from The Society of Thoracic Surgeons Adult Cardiac Surgery Database found that coronary artery bypass grafting (CABG) performed off-pump by experienced surgeons is associated with significantly lower perioperative morbidity and mortality compared with on-pump CABG, while long-term survival outcomes were largely equivalent across techniques.
The study, led by John Puskas, MD, chief of cardiothoracic surgery, Emory University Hospital Midtown, analyzed outcomes for nonemergency, isolated CABG procedures performed between 2008 and 2023. Investigators used the STS National Database—one of the world’s most robust clinical registries—to compare off-pump CABG (OPCAB) and on-pump CABG (ONCAB) when each approach was performed by surgeons with extensive, technique-specific experience. Long-term survival was determined through linkage to the National Death Index and Centers for Medicare & Medicaid Services inpatient data, with follow-up extending through December 2024.
To ensure a rigorous comparison, the analysis included only surgeons meeting strict criteria for experience and procedural volume, and outcomes were assessed using intention-to-treat methodology. More than 184,000 OPCAB cases and 1.34 million ONCAB cases were identified. After propensity matching based on 64 preoperative variables, researchers created more than 184,000 closely matched patient pairs.
Results showed that patients undergoing OPCAB experienced significantly better perioperative and 30-day outcomes, including lower operative mortality, reduced rates of stroke, atrial fibrillation, renal failure, reoperation, prolonged ventilation, and blood transfusion. However, OPCAB was associated with higher rates of incomplete revascularization and a slightly lower average number of grafts per patient, while use of multiple arterial grafts was more common in the off-pump group.
Long-term analysis revealed that the early survival advantage seen with OPCAB diminished over the first five years following surgery. At 15 years, a small survival advantage re-emerged among patients with single-vessel coronary artery disease, but no significant long-term survival difference was observed in patients with multivessel disease.
“These findings highlight that when performed by experienced surgeons, both off-pump and on-pump CABG can deliver excellent long-term outcomes,” said Dr. Puskas. “Patients at high risk for operative/perioperative morbidity and mortality may benefit most from OPCAB by an experienced OPCAB surgeon. Our results emphasize the importance of surgeon experience, complete revascularization, and use of multiple arterial grafts—regardless of surgical technique and may support the concept of coronary surgery as a subspecialty of adult cardiac surgery, benefiting from specialized training and expertise.”
According to the investigators, the study underscores the value of the STS National Database in answering complex, clinically relevant questions that cannot be addressed through randomized trials alone. The scale, depth, and long-term follow-up of STS data allowed researchers to examine outcomes across 15 years in a real-world population while accounting for surgeon experience and patient complexity.
About STS
Founded in 1964, The Society of Thoracic Surgeons is a not-for-profit organization representing more than 8,000 cardiothoracic surgeons, researchers, and allied healthcare professionals worldwide who are dedicated to ensuring the best possible outcomes for surgeries of the heart, lung, and esophagus, as well as other surgical procedures within the chest. The Society’s mission is to enhance the ability of cardiothoracic surgeons to provide the highest quality patient care through education, research, and advocacy.