Effect of acute exercise on the raised plasma fibrinogen, soluble P-selectin and von Willebrand factor levels in chronic atrial fibrillation

Background: There is increasing evidence that chronic atrial fibrillation ( AF) is associated with a prothrombotic or hypercoagulable state. Hypothesis: This study was undertaken to determine whether short-term exerc ise in patients with chronic AF would shift the overall hemostatic balance toward a more prothrombotic state with a reduction in fibrinolytic potentia l. Methods: We recruited 20 patients (13 men; mean age 65 years +/- 11 standar d deviation [SDI) with chronic AF who were not treated with antithrombotic therapy and exercised them to exhaustion using a multistage treadmill exerc ise (standard Bruce) protocol. Blood samples were taken pre exercise, immed iately after cessation of exercise, and at 20 min post exercise. The prothr ombotic state was quantified by fibrinogen tan index of hemorheology and a coagulation factor), soluble P-selectin (sP-sel, marking platelet activatio n), von Willebrand factor (VWF, an index of endothelial dysfunction), and p lasminogen activator inhibitor-1 (PAI-1, a regulator of fibrinolytic activi ty) levels. There were two groups of age- and gender-matched controls in si nus rhythm: (1) healthy controls, and (2) "hospital controls" who were pati ents with vascular disease. Results: Baseline levels of vWf (p = 0.034) and fibrinogen (p < 0.0001), bu t not sP-sel (p = 0.075) were significantly elevated in patients with AF co mpared with both control groups in sinus rhythm. The PAI-1 levels were high est in the hospital control patients, but not in chronic AF (p = 0.041). Fo llowing treadmill exercise, achieving a mean metabolic equivalent of 4.9 ME TS (<plus/minus> 1.75 SD) and total exercise duration of 4.9 min (+/- 2 SD) , there was a significant rise in plasma fibrinogen (repeated measures anal ysis of variance [ANOVA] p = 0.037) and a reduction in PAI-1 levels (p = 0. 025) in patients with AE There were no significant changes seen in vWf (p = 0.308) or sP-sel (p = 0.071) levels. No significant changes in these indic es were seen in hospital controls (all p = not significant). despite a much longer duration of exercise with greater workload. Conclusion: Patients, with chronic AF have increased vWf and fibrinogen lev els compared with sinus rhythm. Exercise to exhaustion influences the hyper coagulable state in chronic AF, with a rise in plasma fibrinogen and possib le increase in fibrinolytic activity. Nevertheless, acute exercise does not appear to have a significant influence on endothelial dysfunction or plate let activation in patients with AF.