Mediastinal radiation therapy for breast cancer in female patients is an independent risk factor for atrial fibrillation recurrence post-catheter ablation

Background: The aim of this study was to assess the safety, efficacy, and predictors of outcomes for atrial fibrillation (AF) ablation in patients with a history of breast cancer. Methods: Consecutive patients with a history of breast cancer undergoing AF ablation from January 2010 to December 2021 were propensity matched in a 1:1 ratio to patients without a history of any cancer. The primary outcome was procedural efficacy, defined by clinical AF recurrence and repeat catheter ablation. The secondary outcome was an assessment of safety looking at eight peri-procedural events. Results: Our cohort was comprised of 82 female patients, 41 patients with a history of breast cancer (mean age, 74.6 ± 7.4 years), and 41 patients with no history of cancer (76.7 ± 8.1 years). Both groups had similar echocardiographic, baseline, and arrhythmia characteristics. Breast cancer patients were at an increased risk of AF recurrence post-ablation compared to non-cancer patients (OR 2.68, 95% CI 1.05–6.86, p = 0.04). Multivariate analysis found prior mediastinal radiotherapy (OR 4.79, 95% CI 1.34–17.1) and AF diagnosis to ablation time (OR 1.2, 95% CI 1.03–1.29) were both independent predictors of AF recurrence post-ablation. Conclusion: Our study suggests that female patients with a history of breast cancer are at a higher risk of developing AF recurrence after catheter ablation. Multivariate analysis showed that patients with a history of prior mediastinal radiation therapy and AF diagnosis to time to ablation were both independent risk factors.