Abstract 11637: Physical Activity and Atrial Fibrillation: Results From the Multi-ethnic Study of Atherosclerosis (MESA)

Abstract

Introduction: Prior studies have raised the question of whether an association exists between physical activity (PA) and atrial fibrillation (AF), with mixed results. We sought to use the Multi-Ethnic Study of Atherosclerosis (MESA) database to examine the association between PA and AF in a diverse population without clinically recognized prevalent cardiovascular disease (CVD). Hypothesis: Increased exercise will have a protective influence on AF incidence. Methods: MESA participants (N=5793) with a completed baseline PA survey and complete covariate data were included. Incident AF events were determined based on hospital discharge ICD-9 codes and Medicare inpatient claims. Total intentional exercise (TIE), defined as a sum of walking for exercise, dance/sport, and conditioning, was used as our independent variable of interest. The MESA population was stratified based on whether they reported participation in any vigorous physical activity (VPA), which was defined as “heavy effort” expended in household chores, lawn/yard/garden/farm work, conditioning activities, and occupational/volunteering work. Cox models, adjusted for demographics and CVD risk factors, were used to determine hazard ratios (HR) for incident AF based on total intentional exercise (TIE) for the subgroups. We performed similar analyses using TIE as a categorical variable stratified into tertiles. Results: During a mean follow-up of 7.7±1.9 years, 199 AF cases occurred. In the overall MESA population, TIE alone was not associated with incident AF. However, within the group that reported any VPA (N=1866), there was a statistically significant protective influence of increasing TIE on incident AF (HR=0.658, p=0.014). Additionally, among the same group, the top tertile of TIE was associated with a significantly lower risk of incident AF compared with the group with no TIE (HR=0.48, p=0.048). Conclusions: TIE was associated with a lower risk of incident AF among those that participated in any VPA, and this protective influence was most notable among those that performed the most TIE. Perhaps as importantly, no subgroup of participants demonstrated an increased risk of incident AF with TIE. These results re-emphasize the beneficial role of exercise for cardiovascular health.