Keynote Lecture: Concomitant Surgical Ablation of Atrial Fibrillation – Current Status and Recommendations
Key Summary
- Approximately 100 000 US patients undergoing cardiac surgery annually have preoperative atrial fibrillation (AF); untreated AF is associated with a 20% reduction in 10-year survival.
- Concomitant surgical AF ablation significantly reduces long-term stroke and improves survival; however, despite receiving a Class 1A recommendation from STS and ESC, the practice is underutilized.
- Lesion set selection should be tailored to AF type: effective strategies include box lesion plus left atrial appendage occlusion for paroxysmal AF (~80% success) and maze III/IV for non-paroxysmal AF (>90% success).
Introduction
At his Cardiovascular Research Technologies (CRT) Keynote Lecture, Dr James L. Cox of Northwestern University emphasized the importance of treating atrial fibrillation (AF) during cardiac surgery, underscoring that failure to do so significantly worsens long-term outcomes. The presented data showed that concomitant surgical AF ablation during coronary artery bypass grafting (CABG) and valve surgery reduces stroke and improves survival, yet remains underutilized in clinical practice despite Class IA guideline recommendations.
Session Highlights
Impact of AF Treatment on Stroke and Survival
The session opened with historical data from Cleveland Clinic demonstrating that patients undergoing mitral valve surgery with untreated preoperative AF experienced worse 15- and 20-year survival. Contemporary estimates indicate that of the total annual mitral valve, aortic valve, and CABG surgeries performed in the United States, about 100 000 patients present with preoperative AF. Prevalence varies by procedure: ~34% of patients undergoing mitral valve surgery, ~18% undergoing aortic valve surgery, and ~10% of patients undergoing CABG (though the overall number of CABG patients is much higher).
Long-term stroke reduction was a central theme, with multiple strategies and studies featured. In an 11.5-year follow-up of medically refractory AF patients treated with the Cox-maze procedure, 68 strokes were predicted based on their CHA2DS2-VASc score; only 1 occurred.1 At 15 years, this procedure has demonstrated freedom from stroke at 99.3%, with 65% of patients off anticoagulation. A 2006 study showed an approximately a 15% improvement in long-term stroke-free survival in treated vs untreated AF.2
The LAAOS III trial demonstrated that surgical left atrial appendage occlusion (LAAO) performed at the time of cardiac surgery significantly reduced long-term stroke.3 However, neither LAAO alone nor surgical ablation alone were as successful as LAAO plus ablation, as reported by a 2024 study of Medicare patients.4
In terms of survival data, a 2012 analysis from Northwestern University demonstrated improved 5-year survival when AF was surgically treated vs not treated during mitral valve surgery.5 A Washington University cohort later showed a 20% improvement in 10-year survival across cardiac surgery types when AF was ablated concomitantly.6 In 2019, the Northern New England Cardiovascular Disease Study Group published an analysis of over 2700 patients reporting a 10% improvement in 5-year survival among CABG, valve, and combined procedures.7
Lesion Strategy Selection
Dr Cox presented detailed slides to illustrate the importance of adopting the correct lesion strategy for each case. First and foremost, the operator must determine whether the patient has paroxysmal or non-paroxysmal AF; this will dictate which course to take, as effectiveness varies widely between types. For example, for paroxysmal AF, a box lesion encircling the pulmonary veins plus LAA occlusion yields 80% success, as does left-sided maze. In contrast, non-paroxysmal AF requires more extensive lesion sets: box lesion strategies with or without LAAO have a success rate of 30%, while left-sided maze procedures achieve 70% success. The exception is the use of the biatrial maze III/IV procedure, which exceeds a 90% success rate in both groups.
Expert Perspectives
Decades of data have contributed to Class 1A recommendations for concomitant AF ablation and cardiac surgery from the Society of Thoracic Surgeons (STS) and European Society of Cardiology (ESC). Despite this, in the past 4 to 5 years, more than 75% of eligible patients in the United States did not receive the recommended treatment.
This highlights a treatment paradox: left internal mammary artery grafting to the left anterior descending artery—associated with a 10% 10-year survival benefit—is adopted in 99% of cases, whereas AF ablation, associated with a 20% survival benefit over the same time frame, is performed in less than 25% of cases.
Implications for Practice
For cardiac surgeons and heart teams, the data strongly support routine concomitant AF ablation during CABG and valve surgery. Procedure selection should be individualized by AF type: key takeaways include the inadequacy of pulmonary vein isolation for treating non-paroxysmal AF, and the high success rates of maze III/IV for both AF types. Perhaps most importantly, based on current society recommendations and the supporting data, failure to treat AF does not meet contemporary standards of care and may even carry legal consequences.
Conclusions
Concomitant surgical ablation for atrial fibrillation improves long-term stroke freedom and survival in patients undergoing cardiac surgery. With strong guideline endorsement and durable outcome data, expanding adoption represents a critical opportunity to improve cardiovascular outcomes nationwide.
James L. Cox, MD, is the Surgical Director of the Center for Heart Rhythm Disorders, the Director of the Comprehensive Atrial Fibrillation Program at Bluhm Cardiovascular Institute, and a Professor of Surgery at Feinberg School of Medicine, Northwestern University.
References
- Cox JL, Ad N, Palazzo T. Impact of the maze procedure on the stroke rate in patients with atrial fibrillation. J Thorac Cardiovasc Surg. 1999;118(5):833-840. doi:10.1016/s0022-5223(99)70052-8
- Itoh A, Kobayashi J, Bando K, et al. The impact of mitral valve surgery combined with maze procedure. Eur J Cardiothorac Surg. 2006;29(6):1030-1035. doi:10.1016/j.ejcts.2006.03.028
- Whitlock RP, Belley-Cote EP, Paparella D, et al; LAAOS III Investigators. Left atrial appendage occlusion during cardiac surgery to prevent stroke. N Engl J Med. 2021;384(22):2081-2091. doi:10.1056/NEJMoa2101897
- Mehaffey JH, Hayanga JWA, Wei L, Mascio C, Rankin JS, Badhwar V. Surgical ablation of atrial fibrillation is associated with improved survival compared with appendage obliteration alone: an analysis of 100,000 Medicare beneficiaries. J Thorac Cardiovasc Surg. 2024;168(1):104-116.e7. doi:10.1016/j.jtcvs.2023.04.021
- Lee R, McCarthy PM, Wang EC, et al. Midterm survival in patients treated for atrial fibrillation: a propensity-matched comparison to patients without a history of atrial fibrillation. J Thorac Cardiovasc Surg. 2012;143(6):1341-1351.
- Musharbash FN, Schill MR, Sinn LA, et al. Performance of the Cox-maze IV procedure is associated with improved long-term survival in patients with atrial fibrillation undergoing cardiac surgery. J Thorac Cardiovasc Surg. 2018;155(1):159-170. doi:10.1016/j.jtcvs.2017.09.095
- Iribarne A, DiScipio AW, McCullough JN, et al. Northern New England Cardiovascular Disease Study Group. Surgical atrial fibrillation ablation improves long-term survival: a multicenter analysis. Ann Thorac Surg. 2019;107(1):135-142. doi:10.1016/j.athoracsur.2018.08.022
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