Impacts of sinus rhythm maintenance with catheter ablation on exercise tolerance in patients with paroxysmal atrial fibrillation

Background: It has been recently reported that sinus rhythm (SR) maintenance with catheter ablation therapy improves exercise tolerance (ET) in patients with persistent atrial fibrillation (AF). However, it remains to be elucidated whether this is also the case for patients with paroxysmal AF (PAF). Methods: We enrolled consecutive 54 patients with PAF (age; 63 ± 10 [SD] years old, male/female 46/8) and 26 patients with persistent AF (non-PAF) (age; 57 ± 12 [SD] years old, male/female 23/3) who underwent AF ablation without recurrence. ET and cardiac function were evaluated by cardio-pulmonary exercise test and ultrasound echocardiography before and 6 months after ablation. Results: The parameters of cardiopulmonary exercise test were comparable between the 2 groups. When PAF group was divided into 2 groups according to the time since diagnosis, peak oxygen uptake (peak VO₂) before ablation was significantly lower in patients with PAF duration of more than 1 year (n = 26), compared with those with less than 1 year (n = 28) (18.1 ± 3.7 vs 21.3 ± 5.8 ml/kg/min, P = 0.022). At 6 months after SR maintenance without AF burden, peak VO₂ significantly improved in both PAF (19.8 ± 5.1 to 22.0 ± 4.8 ml/kg/min, P = 0.0001) and non-PAF (20.6 ± 3.9 to 23.4 ± 5.0 ml/kg/min, P < 0.01). Furthermore, the improvement rate of peak VO₂ after successful ablation had a highly significant inverse relationship with peak VO₂ at baseline in patients with PAF (r = − 0.48, P = 0.0003). Conclusions: These results indicate that SR maintenance with ablation improves ET in patients with PAF, especially in those with reduced ET.