Effects of acute exercise on hemorheological, endothelial, and platelet markers in patients with chronic heart failure in sinus rhythm

Background: Chronic heart failure (CHF) is associated with an increased ris k of thrombosis and thromboembolic events, including stroke and venous thro mboembolism, which may be related to a prothrombotic or hypercoagulable sta te. Acute vigorous exercise has been associated with activation of hemostas is, and this risk may well be particularly increased in patients with CHE Hypothesis: The study was undertaken to determine whether acute exercise wo uld adversely affect abnormalities of hemorheological (fibrinogen, plasma v iscosity, hematocrit), endothelial (von Willebrand factor), and platelet ma rkers (soluble P selectin) in patients with CHF. Methods: We studied 22 ambulant outpatients (17 men; mean age 65 +/- 9 year s) with stable CHF (New York Heart Association class II-III and a left vent ricular ejection fraction of less than or equal to 40%) who were exercised to exhaustion on a treadmill. Results were compared with 20 hospital contro ls (patients with vascular disease, but free of CHF) and 20 healthy control s. Results: Baseline von Willebrand factor (p = 0.01) and soluble P-selectin ( p = 0.006) levels were significantly elevated in patients with CHF when com pared with controls. In the patients with CHF who were exercised, plasma vi scosity, fibrinogen, and hematocrit levels increased significantly, both im mediately post exercise and at 20 min into the recovery period (repeated me asures analysis of variance, all p < 0.05). There was a positive correlatio n between exercise workload and the maximal changes in plasma viscosity in the patients with CRF (Spearman r = 0.5, p = 0.02). Plasma viscosity levels increased with exercise in the hospital control group, although no other e xercise-induced changes were noted in this group. Conclusion: The present study indicates that the hemorheological indices, f ibrinogen, and hematocrit specifically increase during acute exercise in pa tients with CHF. Although moderate exercise should be encouraged in patient s with CHF, vigorous exercise should probably be avoided in view of its pot ential prothrombotic effects in this high-risk group of patients.