Higher baseline cardiorespiratory fitness is associated with lower arrhythmia recurrence and death after atrial fibrillation ablation

BACKGROUND Cardiorespiratory fitness (CRF) has been shown to correlate with incident atrial fibrillation (AF) and AF burden. In recent years there has been increasing recognition of the pivotal role of modifying risk factors before AF ablation. OBJECTIVE The purpose of this study was to investigate whether higher baseline CRF measured using exercise stress testing (EST) was associated with improved outcomes after AF ablation. METHODS We studied 591 patients who underwent EST within 12 months before AF ablation. Patients were categorized into low (<85% predicted), adequate (85%-100% predicted), and high (>100% predicted) CRF groups. Outcomes of interest included arrhythmia recurrence, cessation of antiarrhythmic therapy, repeat hospitalization for arrhythmia, repeat rhythm control procedures, and all-cause mortality. RESULTS During mean follow-up of 32 months after ablation, arrhythmia recurrence was observed in 79% of patients in the low CRF group compared to 54% in the adequate CRF group and 27.5% in the high CRF group (P <.0001). Similarly, rates of repeat arrhythmia-related hospitalization, repeat rhythm control procedures, and need for ongoing antiarrhythmic therapy were significantly lower in the high CRF group (P <.0001). Death occurred in 2.5% of patients in the high CRF group compared to 4% in the adequate CRF group and 11% in the low CRF group (P <.0001). In Cox proportional hazards analyses, high CRF was significantly associated with lower arrhythmia recurrence. CONCLUSION Higher CRF is associated with reduced arrhythmia recurrence rates and death among patients undergoing AF ablation. Efforts should be made to enhance CRF before AF ablation.