Impact of Left Atrial Diameter on Long-Term Outcome After Catheter Ablation of Atrial Fibrillation

Background/Objectives: Atrial fibrillation (AF) is closely associated with adverse remodeling of the left atrium (LA). This study evaluated the impact of LA diameter on long-term outcomes following radiofrequency ablation (RFA) of the pulmonary veins and assessed LA and left ventricular (LV) remodeling over a seven-year follow-up period. Methods: A total of 117 patients with symptomatic, drug-refractory AF underwent RFA. Structural remodeling was evaluated using echocardiography. Long-term outcomes were categorized using the Pulmonary Vein Isolation Outcome Degree (PVIOD), a four-level classification reflecting procedural and clinical success. Results: After seven years, 32.5% of patients who achieved successful sinus rhythm maintenance after a single RFA (PVIOD 1) demonstrated significant reverse remodeling of LA and LV. LA diameter decreased from 39.3±0.6 mm to 36.5±0.6 mm (p=0.0007); LV end-diastolic diameter (LVEDD) from 53.1±0.6 mm to 50.9±0.7 mm (p=0.008); LV end-systolic diameter (LVESD) from 34.7±0.8 mm to 32.0±0.1 mm (p=0.005); and LV ejection fraction (LVEF) increased from 56.8±0.8% to 62.1±1.1% (p=0.000008). Among patients with long-term success after multiple procedures (PVIOD 2; 29.1%), LA diameter decreased significantly from 41.9±0.7 mm to 40.2±0.6 mm (p=0.04), without significant ventricular changes. Patients achieving clinical success (PVIOD 3; 14.5%) showed no significant structural changes. Those with procedural and clinical failure (PVIOD 4; 23.9%) exhibited progressive negative remodeling: LA diameter increased from 44.7±0.7 mm to 47.4±0.7 mm (p=0.006); LVEDD from 52.8±0.9 mm to 57.1±0.6 mm (p=0.0006); LVESD from 36.5±1.1 mm to 40.7±1.2 mm (p=0.006); and LVEF decreased from 50.7±1.7% to 43.8±1.8% (p=0.004). Conclusions: Early and successful single RFA performed in patients with normal LA diameter is associated with complete reverse remodeling and prevention of AF recurrence. As LA size increases, the likelihood of achieving durable procedural success decreases, emphasizing the importance of timely intervention before significant left atrial enlargement develops.