Abstract 57: Increased Fitness Attenuates the Risk for Developing Atrial Fibrillation in African-Americans
Introduction: Atrial fibrillation (AF) is associated with increased mortality risk. Some studies indicate that endurance training may increase the rate of progression to AF. However, others dispute this notion. Furthermore, fitness status and atrial fibrillation in African-Americans has not been investigated.
Methods: From 1986 to 2011, a total of 4,401 African-Americans with normal sinus rhythm (mean age 56±11) underwent a routine exercise tolerance testing at Veterans Affairs Medical Centers Washington DC. During a mean follow-up period of 8.0±4.7 years 361 (8.2%) developed AF. To assess the role of fitness status in the development of AF, we formed the following four fitness categories based on peak workload achieved (metabolic equivalents; METs): Least-Fit: ≤ 5METs (≤20%; n=531); Low-Fit: 5.5-7.2 METs (20.1%-50%; n=1,367); Moderate-Fit:7.3-9.0 METs (50.1%-80%; n=1,775); and High-Fit: >9 METs (>80%; n=728). Cox proportional hazards models were applied after adjusting for age, BMI, race, gender, CV disease, CV medications, and cardiac risk factors. P-values <0.05 using two sided tests were considered statistically significant.
Results: The association between exercise capacity and the risk for developing AF was inverse and graded. For every 1-MET increase in exercise capacity the AF-risk was 25% lower (HR=0.75; CI: 0.71-0.81; p<0.001). When compared to the Least-Fit category, the risk for developing AF was 36% lower (HR=0.64; CI: 0.48-0.83; p=0.001) in Low-Fit; 66% (HR=0.44; CI: 0.33-0.60; p<0.001) in Moderate-Fit; and 76% (HR=0.24; CI: 0.14-0.40; p<0.001) in High-Fit individuals.
Conclusions: Aerobic fitness is inversely and independently associated with lower risk for developing AF.
Author Disclosures: C. Faselis: None. P. Kokkinos: None. J. Kokkinos: None. A. Tsimploulis: None. F. Kyritsi: None. A. Pittaras: None. M. Doumas: None. H. Moore: None. P. Karasik: None. R. Fletcher: None.
- © 2014 by American Heart Association, Inc.