Abstract 14665: Higher Numbers of Circulating Endothelial Progenitor Cells are Associated with Better Functional Performance in Patients with Peripheral Artery Disease
Objectives: Growing evidence suggests that circulating endothelial progenitor cells (EPCs) repair damaged endothelium in patients with cardiovascular disease. Ischemia, induced by walking activity in people with peripheral artery disease (PAD), is associated with the release of tissue-resident EPCs into the circulation and homing to ischemic regions. We determined whether higher levels of EPCs are associated with better functional performance among individuals with PAD. We also determined whether EPC levels increase to a greater degree among people with PAD compared to those without PAD.
Methods: Eighteen participants with PAD underwent measurements of EPCs, six-minute walk, four-meter walking velocity, and a treadmill exercise stress test. Physical activity was measured by patient report. EPC levels were measured in participants with and without PAD before and after a maximal exercise stress test. EPCs (CD34+KDR+CD45lo) were quantified using multi-parameter flow cytometry and an ISHAGE based gating strategy.
Results: Among the 18 PAD patients, higher levels of EPCs were associated with better functional performance and higher physical activity levels (Table 1). After a maximal exercise stress test, EPC levels increased to a greater degree among participants with PAD compared to those without PAD (Table 2).
Conclusion: Higher levels of circulating EPCs are associated with better functional performance and higher physical activity among people with PAD. Increases in EPC levels after a maximal exercise stress test may result from ischemia-induced release of EPC. Further study is needed to discern the mechanisms and longitudinal significance of these associations.
- © 2012 by American Heart Association, Inc.