Postablation Atrial Fibrillation Burden and Patient Activity Level: Insights From the DISCERN AF Study

BACKGROUND: Recent evidence shows an association between the level of physical activity and cardiovascular mortality and morbidity in patients with atrial fibrillation (AF). We sought to assess the impact of AF daily burden on the activity level of the patient who underwent pulmonary vein isolation. METHODS AND RESULTS: Patients enrolled in the DISCERN AF (Discerning Symptomatic and Asymptomatic Episodes Pre and Post Radiofrequency Ablation of Atrial Fibrillation) study all had insertable cardiac monitors, which provided the daily burden of atrial tachycardia and atrial fibrillation (AT/AF) and a corresponding activity level. A total of 44 341 daily AT/AF burden points were collected from 50 patients with an average of 887 observations for every patient, with <5 minutes of AT/AF reported on 82.6% of days. The daily burden of AT/AF after ablation ranged between 0 and 1440 minutes. The minimum and maximum daily activity was 0 and 600 minutes per day, respectively. A significant inverse association was detected between activity levels and AF burden (P<0.001; 95% confidence interval, 0.01–0.04). The daily activity starts progressively decreasing after 500 minutes of AF and considerably drops after 1000 minutes. The association between activity level and burden of AT/AF was still statistically significant after adjustment for clinical variables (P =0.02; 95% confidence interval, −003 to 0.04). CONCLUSIONS: Daily activity level correlates with daily AT/AF burden in patients who underwent AF ablation. The daily activity started decreasing after a daily burden of 500 minutes of AF and greatly drops after 1000 minutes. Therefore, the amount of AT/AF burden that may impact the activity level seems to be related to hours and not minutes of arrhythmias. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT00745706.