Left atrial dysfunction still exists in patients who obtain normal left atrial volume after successful ablation of atrial fibrillation

Abstract Introduction Atrial fibrillation (AF) promotes left atrial (LA) remodeling and vice versa. LA volume index (LAVI) ≥34 mL/m2 is an established cut-off value for identifying an enlarged left atrium. Catheter ablation has become an established therapy for AF and provides a reduction of LA volume by maintaining sinus rhythm (reverse remodeling). However, the definition of LA reverse remodeling after AF ablation is undetermined. Purpose We hypothesized that patients with LA dilatation who obtain normal LA volume (LAVI <34 mL/m2) after AF ablation would have better long-term outcomes than those who do not. Furthermore, we investigated whether patients with a normal LA volume could also obtain normal LA function with AF ablation. Methods We enrolled 140 AF patients with baseline LAVI ≥34 mL/m2, without AF recurrence for 1 year after the initial AF ablation. We acquired conventional and speckle-tracking echocardiographic parameters within 24 h and at 1 year after the procedure. Late recurrence was defined as AF recurrence >1 year after the initial ablation. To define the normal range of LA function, age-and sex-matched 140 controls without a history of AF were also enrolled. Results After restoration of sinus rhythm, overall LA structural and functional parameters were significantly improved, and 75 patients (54%) had normal LA volume at the time of follow-up (Table). During a median follow-up of 44 (31–61) months, 32 patients (23%) experienced a late recurrence of AF. Patients who obtained normal LA volume after AF ablation had fewer late recurrences than those who did not (P<0.01) (Figure). However, LA functional abnormalities still existed in AF patients, even if LA volume was normalized as in controls (Table). Conclusion Patients who obtain normal LA volume have better long-term outcomes of AF ablation than those who do not. Although AF ablation promotes beneficial effects on LA structure and function, LA function cannot be normalized even in patients who obtain normal LA volume after successful ablation. Thus, physicians should carefully consider long-term follow-up and residual AF risks, regardless of sinus rhythm restoration by catheter ablation. Funding Acknowledgement Type of funding sources: None.