We thank Dr García-Villarreal [1] for his letter regarding our recent article. We performed a systematic review and meta-analysis of randomized trials that tested prophylactic ablation at the time of cardiac surgery in patients without a history of atrial fibrillation (AF) [2]. We identified seven trials, including six that tested pulmonary vein isolation (PVI) and one that targeted ganglion plexi. Although results for preventing both short-term post-operative AF and long-term clinical AF were promising, we judged the quality of evidence to be low.
Dr García-Villarreal writes expressing concern that PVI was the primary modality studied in the trials, reminds us to consider the full spectrum of available surgical ablation techniques beyond PVI and urges caution about performing prophylactic surgical ablation based on the current data. We agree that any surgical ablation lesion set (from PVI to complex bi-atrial sets including the maze procedure) should not be used at this time prophylactically for patients without a preoperative diagnosis of AF.
To date, in catheter-based ablation, endocardial PVI is the mainstay of ablation for reducing AF in randomized clinical trials, owing to the fundamental role of the PVs in arrhythmogenesis [3]. Many different catheter-based strategies have been tested against PVI in patients with persistent AF, but these have consistently failed to demonstrate incremental benefit for patients. The surgical approach to epicardial ablation offers unparalleled access to arrhythmogenic structures in both atria. Complex surgical lesion sets continue to evolve and are being increasingly recommended by guideline bodies. While these approaches, including contemporary iterations of the Cox maze procedure, have shown great promise in observational studies, they too need to be proven in large clinical trials.
We embarked on our systematic review and meta-analysis with the objective of informing a large, definitive randomized trial to test the efficacy and safety of prophylactic ablation in patients without AF who are having cardiac surgery. Given the proven efficacy of PVI and the incremental risks associated with additional lesion sets (e.g. increased risk of permanent pacemaker [4]), investigators leading the studies included in this meta-analysis likely deemed a PVI-based lesion set to be the appropriate intervention (weighing efficacy and safety) to study in a prophylactic ablation trial.
Conflict of interest: Dr William F. McIntyre has received consulting and speaking fees from AtriCure and iRhythm. He is also supported by a National New Investigator Award from the Heart and Stroke Foundation of Canada. Dr Jeff S. Healey has received research grants and consulting honoraria from Boston Scientific and Medtronic Inc. Dr Richard P. Whitlock has received grants/research support from Boehringer Ingelheim, Bayer, Abbott, AtriCure, Cytosorbents and speaking/consulting fees from Boehringer Ingelheim, PhaseBio, Cryolife, Bayer and Atricure.
Contributor Information
William F McIntyre, Population Health Research Institute, Hamilton Health Sciences and McMaster University, Hamilton, ON, Canada; Division of Cardiology, Department of Medicine, McMaster University, Hamilton, ON, Canada.
Jeff S Healey, Population Health Research Institute, Hamilton Health Sciences and McMaster University, Hamilton, ON, Canada; Division of Cardiology, Department of Medicine, McMaster University, Hamilton, ON, Canada.
Richard P Whitlock, Population Health Research Institute, Hamilton Health Sciences and McMaster University, Hamilton, ON, Canada; Division of Cardiac Surgery, Department of Surgery, McMaster University, Hamilton, ON, Canada.
REFERENCES
- 1. García-Villarreal O. Setting the records straight: surgical ablation misinterpreted and misrepresented in prophylactic studies. Interdiscip Cardiovasc Thorac Surg 2025. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2. Visanji M, Belley-Côté EP, Pandey A et al. Prophylactic ablation during cardiac surgery in patients without atrial fibrillation: a systematic review and meta-analysis of randomized trials. Interdiscip Cardiovasc Thorac Surg 2024;39:ivae195. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3. Haïssaguerre M, Jaïs P, Shah DC et al. Spontaneous initiation of atrial fibrillation by ectopic beats originating in the pulmonary veins. N Engl J Med 1998;339:659–66. [DOI] [PubMed] [Google Scholar]
- 4. McClure GR, Belley-Cote EP, Jaffer IH et al. Surgical ablation of atrial fibrillation: a systematic review and meta-analysis of randomized controlled trials. Europace 2018;20:1442–50. [DOI] [PubMed] [Google Scholar]