A study of more than one million patients undergoing isolated coronary artery bypass graft (CABG) surgery has found that multi-arterial grafting CABG is associated with superior long-term survival compared to single arterial grafting.
The research, presented at the 60th annual meeting of the Society of Thoracic Surgeons (STS 2024; 27–29 January, San Antonio, USA) and published simultaneously in The Annals of Thoracic Surgery examines the ongoing controversy surrounding the choice between multi-arterial grafting and single-arterial grafting in CABG for multivessel coronary revascularisation.
“Controversy persists as to whether multi-arterial grafting improves long-term survival over CABG with single-arterial grafting with saphenous vein conduits, thus limiting wider adoption in the USA,” Joseph Sabik (Cleveland Medical Center, Cleveland, USA) and colleagues write in their Annals paper.
The time and technical requirements of multi-arterial grafting, often with bilateral internal thoracic artery and/or radial artery conduits, are elevated compared to a single-arterial grafting strategy, they note, adding that though several single-centre reports have shown that patients who receive multi-arterial grafting may experience better survival, recent studies, including the randomised Arterial Revascularization Trial (ART) of single versus bilateral internal thoracic artery CABG did not detect an overall difference. However, the secondary analyses of the ART trial did indeed identify a long-term survival benefit of multi-arterial grafting when stratified by as-treated groups and surgeon experience.
The latest research, spanning from 2008 to 2019 and involving over one million patients undergoing isolated CABG with more than two bypass grafts, found that multi-arterial grafting CABG is associated with superior long-term survival compared to single arterial grafting, establishing it as the preferred surgical strategy for multivessel revascularisation.
“Multiple small studies have demonstrated a survival benefit of multi-arterial grafting. We wanted to know if this survival benefit of multi-arterial grafting observed in single-centre studies would translate to a large national cohort,” said Sabik. “Using the STS Adult Cardiac Surgery Database, we were able to demonstrate that it does.”
At 10 years, multi-arterial grafting demonstrated improved unadjusted (hazard ratio [HR] 0.59, 95% CI 0.58‒0.61) and adjusted (HR 0.86, 95% CI 0.85‒0.88) survival rates compared to single-arterial grafting. A centre volume of 10 or more multi-arterial grafting cases per year was associated with survival benefits.
Multi-arterial grafting’s survival advantage over single-arterial grafting was found in various sub-groups, including stable coronary disease, acute coronary syndrome, and acute infarction. Notably, multi-arterial grafting showed superior survival for patients with a body mass index (BMI) less than 40, whereas patients with a BMI of 40 or higher had superior survival with single-arterial grafting. Survival outcomes were equivalent between multi-arterial grafting and single-arterial grafting for patients aged 80 years or older, and those with severe heart failure, renal failure, peripheral vascular disease, or obesity.
Patient data was collected from the STS Adult Cardiac Surgery Database and linked to the National Death Index for comprehensive longitudinal survival analysis. Risk-adjustment measures, including inverse probability weighting and multivariable modelling, were implemented to ensure accurate comparisons.
These findings have significant implications for clinicians and cardiac surgeons when deciding on the most appropriate multivessel revascularisation approach, the researchers suggest.
“The survival benefit of multi-arterial grafting was observed in nearly all patients, except in those 80 or older and in those with co-morbidities graded as severe, where multi and single-arterial grafting resulted in similar survival. The only patients where single arterial grafting resulted in better survival were severely obese,” said Sabik.
