Radiofrequency ablation in patients undergoing mitral valve surgery with or without giant left atria: A retrospective, single-center, cohort study

Abstract

Background For patients with giant left atria, outcomes of surgical ablation remain controversial. We aimed to compare the efficacy of radiofrequency ablation between patients undergoing mitral valve surgery with and without giant left atria. Methods This retrospective, single-center, cohort study investigated patients who underwent mitral valve surgery and concomitant radiofrequency ablation from 2009 to 2019. Patients were divided into non-giant left atria (diameter ≤65 mm, n=1,543) and giant left atria (diameter >65 mm, n=241) groups. Five-year freedom from atrial tachyarrhythmia recurrence and thromboembolic event rates were assessed with death as the competing risk factor with and without propensity-score matching. Results Patients with giant left atria had higher mortality (10.8% versus 6.2%, P=0.008) and readmission rates for heart failure than those without (12.0% versus 6.8%, P=0.004). Atrial tachyarrhythmia recurrence rates were higher in patients with giant left atria than those without (49% versus 24% at 5 years, P<0.001), but the cumulative incidence of thromboembolic events before (P=0.944) and after (P=0.695) propensity-score matching were comparable. Conclusions Radiofrequency ablation effectively prevented thromboembolic events in patients with giant left atria, despite significant atrial tachyarrhythmia recurrence. Atrial tachyarrhythmia recurrence did not increase the risk of thromboembolic events. A lower success rate should be considered when deciding whether to perform surgical ablation in patients with giant left atria.