Successful catheter ablation improves exercise tolerance in persistent atrial fibrillation patients, especially those with reduced ventricular contraction, preserved atrial function, or a high CHADS2 score.

Abstract

BACKGROUND\nIt has been reported that rhythm control for persistent atrial fibrillation (per-AF) patients by catheter ablation improves their exercise tolerance, subjective symptoms, and quality of life (QoL). However, clinical factors that can predict future improvement of exercise capacity after successful catheter ablation in per-AF patients are unclear.\n\n\nMETHODS\nThis study consisted of 62 patients (mean age 65.6\u202f±\u202f8.7 years, 77% males) with per-AF who underwent catheter ablation from June 2017 to May 2018. All patients were subjected to extended pulmonary vein isolation. Exercise tolerance was evaluated using a symptom-limited cardiopulmonary exercise test before and 3 months after catheter ablation. Primary endpoints were QoL measurements using an original questionnaire and functional assessments performed at 3 months.\n\n\nRESULTS\nThe questionnaire revealed significant improvement in QoL after catheter ablation (minimal metabolic equivalents occurring symptoms: from 5.48\u202f±\u202f1.14 to 5.64\u202f±\u202f1.06; p\u202f=\u202f0.01). Endurance exercise characteristics improved significantly after catheter ablation, demonstrated by a shift in anaerobic threshold (from 13.3\u202f±\u202f3.0 to 15.2\u202f±\u202f3.3\u202fml/kg/min; p\u202f<\u202f0.001), peak oxygen uptake (from 19.1\u202f±\u202f4.6 to 22.5\u202f±\u202f5.0\u202fml/kg/min; p\u202f<\u202f0.001), and minute ventilation vs carbon dioxide production slope (from 28.3\u202f±\u202f6.1 to 25.7\u202f±\u202f3.8; p\u202f<\u202f0.001). Multivariate Cox regression analysis revealed that a decreased left ventricular ejection fraction, high left atrial appendage velocity, and high CHADS2 score were identified as independent predictors of anaerobic threshold and a peak value of oxygen uptake with more than 20% improvement.\n\n\nCONCLUSIONS\nCatheter ablation for per-AF patients improves QoL and exercise tolerance. The effect was especially remarkable in patients with reduced ventricular function, those who had a preserved atrial function, or those at high risk of thromboembolism.