Introduction: The indication of suitability of ablation for long-persistent atrial fibrillation (CAF) remains to be studied. CAF patients, likely less symptomatic, can have lower exercise capacity (EC). Hence we investigated whether EC testing prior to attempting further procedures could be used as a determinant for suitability of sinus rhythm (SR) maintenance in CAF patients.
Methods: For 36 consecutive CAF (>1 year) patients, we sought to maintain SR using ablation with anti-arrhythmic drugs. EC was evaluated before procedures and after 6 months SR maintenance. For 32 cases, SR was maintained for 27.4±6.9 months. EC parameters varied before procedures. (Peak VO2. % of predicted: 38% to 124%; median: 80%, VE/VCO2-slope: 14.8 to 41.5; median: 25.9). Patients with better EC had greater stroke volume index, lower pulmonary vascular resistance and better diastolic function. After SR maintenance, the peak VO2 improved to 87% (P<0.01), though percentage changes in VE/VCO2-slope varied (-23.2% to 27.1%; median: 4.2%). However, greater EC improvements were observed in patients with lower EC (Peak VO2: R2=0.41; VE/VCO2-slope: R2=0.61, P<0.01).
Conclusions: We conclude CAF patients with lower EC can more benefit from aggressive SR maintenance.