Abstract 15575: Can Rhythm Control by Catheter Ablation Improve Exercise Capacity in Asymptomatic Patients With Chronic Atrial Fibrillation?
Introduction: Radiofrequency catheter ablation (RFCA) for asymptomatic atrial fibrillation (AF) is not indicated due to limited data on it’s clinical efficacy. This study evaluated the change in oxygen kinetics and cardiopulmonary performance parameters after RFCA for asymptomatic (Canadian Cardiovascular Society-Severity of AF scores = 0) Chronic AF patients.
Methods: A total of 57 patients with asymptomatic chronic AF (age 60 ± 9 year-old, 89.5% male, AF duration 51 ± 49 months) divided into 2 groups according to sinus rhythm conversion via RFCA: Group 1 (Rate control, n=32); Group 2 (Rhythm control, n=25). The patients who achieved sinus rhythm by antiarrhythmics (n=20) and cardioversion (n=4) were excluded. All underwent two times of treadmill cardiopulmonary exercise tests (modified Bruce protocol, Quark CPET®, COSMED, Italy) before and after each treatment (follow-up periods, 250 ± 181 days). Peak oxygen uptake (Peak VO2, ml/min/Kg) as aerobic capacity, O2-pulse at peak (ml/beat) for cardiovascular response, and the slope of the increase in ventilation to the increase in CO2 output (VE-VCO2 slope) for gas exchange were compared.
Results: The Group 1 patients were older (62 ± 7 vs. 57 ± 10 year-old) and had longer duration of AF (63 ± 52 vs. 36 ± 39 months) than the Group 2 patients. The O2-pulse at peak were much increased in Group 2 during follow-up periods (Group 1, from 10.0 ± 3.1 to 10.6 ± 3.1, P=0.137; Group 2, 12.1 ± 3.8 to 15.4 ± 3.8, P=0.003). During exercise, maximal exercise heart rate was significantly lower in Group 2 after treatment (Group 1, 162±25 vs. Group 2, 128±29 bpm, P<0.001). However, the value of Peak VO2 and VE-VCO2 slope were not different between before and after treatment, and between 2 groups.
Conclusion: The results from the present study indicate that improvement of maximal aerobic capacity and exercise tolerance are negligible in asymptomatic patients with chronic AF following successful catheter ablation.
Author Disclosures: J. Nam: None. C. Lee: None. K. Park: None. J. Son: None. U. Kim: None. J. Park: None. D. Shin: None. Y. Kim: None.
- © 2015 by American Heart Association, Inc.