AUTHOR=Sun Xuerong , Zhao Shuang , Chen Keping , Hua Wei , Su Yangang , Xu Wei , Wang Fang , Fan Xiaohan , Dai Yan , Liu Zhimin , Zhang Shu 

TITLE=Association Between Changes in Physical Activity and New-Onset Atrial Fibrillation After ICD/CRT-D Implantation

JOURNAL=Frontiers in Cardiovascular Medicine

VOLUME=Volume 8 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/cardiovascular-medicine/articles/10.3389/fcvm.2021.693458

DOI=10.3389/fcvm.2021.693458

ISSN=2297-055X

ABSTRACT=Background: Changes in physical activity (PA) after implantable cardioverter defibrillator (ICD) or cardiac resynchronization therapy defibrillators (CRT-D) implantation were unknown. The association of PA changes with new-onset atrial fibrillation (AF), cardiac death and all-cause mortality was unclear in patients at high risk of sudden cardiac death.
Methods: Patients receiving ICD/CRT-D implantation from SUMMIT registry were retrospectively analyzed. Changes in PA were considered from baseline status to 1 year after implantation. New-onset AF was defined as the first atrial high-rate episode ≥1% of the daily AF burden detected after implantation. 
Results: Over a mean follow-up of 50.3 months, 124 new-onset AF events (36.2%), 61 cardiac deaths (17.8%) and 87 all-cause deaths (25.4%) were observed in 343 patients with ICD/CRT-D implantation. PA at 1 year after implantation was increased compared with PA at baseline (11.97±5.83% vs 10.82±5.43%, P=0.008), and PA at 1 year was improved in 210 patients (61.2%).  Per 1% decrease in PA was associated with 12.4%, 18.3% and 14.3% higher risks of new-onset AF, cardiac death and all-cause mortality, regardless of different baseline characteristics. Patients with decreased PA had two-fold risks of new-onset AF (hazard ratio [HR]=1.972, 95% confidence interval [CI]: 1.352-2.877, P<0.001) as high as those with unchanged/increased PA. Decreased PA was an independent risk factor for cardiac death (HR=3.358, 95% CI: 1.880-5.996, P<0.001) and all-cause mortality (HR=2.803, 95% CI:1.732-4.535, P<0.001). 
Conclusion: PA decrease after ICD/CRT-D implantation is associated with a higher incidence of new-onset AF, resulting in worsened outcomes in cardiac death and all-cause mortality.