Abstract 20388: Impact of Changes in Cardiorespiratory Fitness on Incidence of Atrial Fibrillation/Flutter
Background: The benefits of regular exercise in improving cardiovascular health are well recognized; however, the impact of changes in cardiorespiratory fitness on the incidence of atrial fibrillation/ flutter (A-Fib/Flutter) is less clear.
Methods: From 1993 through 2010, all patients undergoing a clinically indicated treadmill exercise test (TMET) at the Mayo Clinic Integrated Stress Center, Rochester, MN were identified (N= 76,857). From this, Olmsted and neighboring counties residents and who had at least two TMETs were selected (N=3,696). Cardiorespiratory fitness as expressed in form of functional aerobic capacity (FAC) was computed from age and sex-specific TMET performances. The subjects were divided into fit (FAC ≥100%), less-fit (80-99%), and unfit (FAC<80%) cardiorespiratory fitness groups. From this, patients were excluded at time of the second test for: age<18 years, prior history of A-Fib/Flutter or stroke. Final study cohort comprised of 3,109 patients. Patients were prospectively followed from the date of second exercise test until end of January 2016 for occurrences of the A-Fib/Flutter. A-Fib/Flutter diagnoses were ascertained through retrospective chart review. Proportional hazard regression modeling was done to assess relationship of changes in FAC with the outcome with adjustment for age, sex, baseline FAC, and time duration between exercise tests.
Results: Mean age in our study group was 56.8 ± 11.9; females comprised of 36% of the cohort. During an overall median follow-up of 16 (12 to 19) years, 407 patients (13.1%) developed incident A-Fib/Flutter. A 10% higher FAC at baseline was associated with 16% lower risk of incident A-Fib/Flutter. In addition, an interval increase of 10% in FAC decreased the risk of A-Fib/Flutter by 12%; the most significant improvements were seen in the less-fit [0.88(0.79-0.97, p=.01)] and unfit [0.88(0.80-0.97, p<.001)] groups.
Conclusion: Both baseline as well as change in cardiorespiratory fitness independently predict risk of incident A-Fib/Flutter.
Author Disclosures: N. Hussain: None. B.J. Gersh: None. S.A. Joppa: None. F. Lopez-Jimenez: None. S.L. Kopecky: None. R.J. Thomas: None. 1.G. Allison: None.
- © 2016 by American Heart Association, Inc.