Surgical Ablation During CABG Improves Survival in Patients with Preexisting Atrial Fibrillation

Atrial fibrillation (AF) is a common condition among patients undergoing coronary artery bypass grafting (CABG). Surgical ablation for AF during CABG not only restores normal rhythm but may also reduce the risk of tachycardia-related heart failure, a likely factor in the improved long-term survival. Despite existing clinical guidelines supporting its use, the procedure remains underutilized, and less than a third of eligible patients receive it. Now, a new study published in The Annals of Thoracic Surgery provides strong evidence that surgical ablation during isolated CABG significantly improves long-term survival in patients, reinforcing the need for broader adoption of this practice.

The study by clinicians at Baylor Scott & White The Heart Hospital (Plano, TX, USA) is one of the latest in a series of studies evaluating the effectiveness of surgical ablation for AF during CABG. The team used Medicare claims data from over 87,000 patients with preexisting AF who underwent CABG between 2008 and 2019. To ensure that the survival benefits were not skewed by patient selection bias, the researchers used two advanced statistical methods. Overlap propensity score weighting was applied to account for measured differences in patient profiles. Additionally, a surgeon-preference instrumental variable analysis was used to simulate randomization by comparing patients treated by surgeons who frequently perform ablation with those treated by surgeons who rarely do—minimizing the influence of unmeasured confounding factors.

According to the study, only 22% of patients received ablation during the study period. Even after the Society of Thoracic Surgeons issued a Class I recommendation for the procedure in 2017, ablation rates reached just 27% by 2019. The study highlights how surgeon preference plays a critical role in whether patients receive the procedure. Patients who underwent surgical ablation during CABG had a median survival of 7.82 years, compared to 7.46 years for those who did not—a risk-adjusted survival benefit of 4.4 months (P<0.001). Among patients treated by surgeons who commonly perform ablations, the survival advantage increased to nearly five months (7.03 vs. 6.62 years; P<0.001). Notably, the study also found that the survival benefit emerged more than two years post-surgery, suggesting long-term gains.

“This study is one of several recent analyses suggesting that surgical ablation may meaningfully improve survival in patients with preexisting atrial fibrillation undergoing CABG,” said Dr. Justin Schaffer. “Our analysis found that the treatment effect of surgical ablation for AF manifested late, over two years after CABG. We hypothesize this is because ablation leads to a decreased incidence of tachycardia-related heart failure, which translates to improved late survival.”

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Baylor Scott & White The Heart Hospital