Improvement of Maximal Exercise Performance After Catheter-Ablation of Atrial Fibrillation and Its Prognostic Significance for Long-Term Rhythm Outcome

Background Rhythm control may improve functional capacity in patients with atrial fibrillation (AF). Long-term exercise tolerance improvement and its prognostic implications following catheter-ablation (CA) of paroxysmal and nonparoxysmal AF are underreported. Methods and Results Consecutive patients underwent cardiopulmonary exercise testing just before and 12 months after their index CA of AF. Follow-up 24-hour Holter recordings were obtained at 6-month intervals post-CA, and any atrial arrhythmia >30 seconds detected after 3 months postprocedure was considered AF recurrence. Of 110 patients (mean age 57.5±10.6 years, 77.2% males) with paroxysmal AF (n=66) or nonparoxysmal AF (n=44), the 12-month exercise tolerance improved significantly in those who maintained sinus rhythm during the first 12 months post-CA (n=96), but not in patients with AF recurrence (n=14). After CA, the 12-month respiratory exchange ratio at maximal workload significantly increased in patients with paroxysmal AF, whereas those with nonparoxysmal AF significantly reduced their heart rate during the 12-month cardiopulmonary exercise testing (all ≤0.001). During the follow-up of 42.8±7.8 months, a total of 29 patients (26.3%) experienced recurrent AF. On multivariate analysis including patients without recurrent AF at 12 months after CA, the extent of work time improvement at follow-up cardiopulmonary exercise testing was independently associated with the rhythm outcome beyond 12 months postprocedure (hazard ratio of 0.936 [95% CI, 0.894-0.979] for each 10 seconds increase in the work time following ablation, =0.004). Conclusions CA of AF was associated with recovery of exercise intolerance in patients with paroxysmal AF or nonparoxysmal AF. Inability to improve exercise capacity at 12 months post-CA was an independent risk factor for later AF recurrence.