The effects of exercise stress testing on soluble E-selectin, von Willebrand factor, and circulating endothelial cells as indices of endothelial damage/dysfunction.

BACKGROUND

The quantification of circulating endothelial cells (CECs) in whole blood is an increasingly recognized index of endothelial damage/dysfunction. Abnormal CECs have been linked to the severity of coronary artery disease (CAD).

OBJECTIVE

We assessed the relationship of CECs to other markers of endothelial dysfunction (von Willebrand factor (vWF) and soluble E-selectin (sEsel)) during exercise stress testing (EST) in a cohort of patients with suspected CAD.

METHODS

We studied a cohort of patients referred to our chest pain clinic with a history of exertional chest pain. Treadmill EST was performed, using a full Bruce exercise protocol. Blood for CECs (immunobead method), vWF and sEsel (both ELISA) were collected immediately before (pre-exercise), immediately following exercise, and at 30 minutes post-EST.

RESULTS

We studied 31 patients (84% male; mean (SD) age 58.4 (9.8) years). Of the entire cohort, 14 patients (45.2%) had a positive EST. Exercise led to significant increases in levels of CECs, sEsel, vWF, white blood cells (WBC), heart rate, mean and systolic blood pressure compared with base-line (all P < 0.05). There was a significant correlation between the change (delta (immediate post-pre-exercise)) in CECs and delta vWF (r = 0.45; 95% CI 0.11-0.69: P = 0.01) and delta sEsel (r = 0.41; 0.05-0.7: P = 0.02), as well as between delta vWF and delta sEsel (r = 0.55; 0.25-0.76: P = 0.001). Neither absolute nor delta CEC counts were predictive of exercise work-load/functional capacity, nor the presence of positive EST results.

CONCLUSION

EST led to a significant increase in endothelial markers (CECs, vWF, and sEsel) compared with base-line levels. The rise in CECs correlated with the increases in other endothelial markers, but was not related to the either exercise workload/capacity or to the presence of a positive EST.