A Study on Endothelial Function in Patients with Atrial Fibrillation by Cardiac Rehabilitation Exercise Training

Background: Aerobic interval training improves endothelial dysfunction in patients with cardiovascular disease. However, whether this effect occurs in patients with atrial fibrillation is unclear. If it does, how long the effects are sustained for remains to be determined. This randomized controlled trial aimed to evaluate the effects of one-year aerobic interval training on endothelial dysfunction in atrial fibrillation patients. Methods: Seventy-four patients with atrial fibrillation (53 men, 21 women; mean age 63 ± 6 years) were randomized into a one-year continuous aerobic interval training (CT) group, a six-month detraining after six months of aerobic interval training (DT) group, or a medical treatment only (MT) group. Aerobic interval training was performed three times a week for one year or six months, with an exercise intensity of 85%–95% of peak heart rate. The primary outcome was a change in biomarkers of endothelial dysfunction from baseline, six months, or one-year follow-up. Results: Six-months aerobic interval training reduced von Willebrand factor (CT: 103.7 ± 30.7 IU/dL and DT: 106 ± 31.2 IU/dL vs. MT: 145 ± 47.7 IU/dL, p = 0.044). The improvements were maintained with continuous aerobic interval training, although the value increased back to the baseline level upon detraining (CT: 84.3 ± 39.1 IU/dL vs. DT: 122.2 ± 27.5 IU/dL and MT: 135.9 ± 50.4 IU/dL, p = 0.002). Interleukin 1 beta decreased after six months of aerobic interval training (CT: 0.59 ± 0.1 pg/mL and DT: 0.63 ± 0.09 pg/mL vs. MT: 0.82 ± 0.28 pg/mL, p = 0.031), and the improvement was maintained with continuous aerobic interval training and even after detraining (CT: 0.58 ± 0.08 pg/mL and DT: 0.62 ± 0.09 pg/mL vs. MT: 0.86 ± 0.28 pg/mL, p = 0.015). Conclusions: One year of aerobic interval training improves endothelial dysfunction in patients with atrial fibrillation and is primarily associated with the reduction of circulating thrombogenic and pro-inflammatory factors. A definitive way to retain these improvements is to maintain aerobic training for the long term.