Among the benefits of a cardiac rehabilitation (CR) program for patients after an acute coronary syndrome (ACS) is the mobilization of endothelial progenitor cells (EPCs). However not all patients respond to CR with an increase of EPC. We performed this study to identify the characteristics of patients who will not benefit from an increase of EPCs at the end of a CR program.

112 ACS patients were admitted to a four-week CR program. EPCs, high sensitivity C-reactive protein (hsCRP) and NT-ProBNP levels were determined at the beginning (T1) and at the end (T2) of the CR program. All patients performed a cardiopulmonary exercise test at T1 and at T2. EPCs were defined as CD34+KDR+, CD133+KDR+ and CD34+CD133+KDR+. hsCRP and NT-ProBNP were measured by nephelometric and immunometric method, respectively.

At T2, we observed a significant increase of EPCs (p = 0.001), VO₂ peak, Watt max HDL-cholesterol (p < 0.0001) and a significant decrease (p < 0.001) of hsCRP and NT-ProBNP, triglycerides, HbA1c, systolic blood pressure and waist circumference. Variations of VO₂ peak were significantly correlated with the variations of EPCs. Patients with increased EPCs showed significantly (p = 0.01) lower baseline levels of CRP and higher basal Watt max (p = 0.04). In a multivariate logistic regression analysis, the lowest tertile of baseline hsCRP significantly affected the likelihood of having an increase of EPCs at the end of the CR program.

A CR program determines an increase of EPCs with a decrease of CRP and NT-ProBNP. A different trend for EPCs can be detected among patients correlated to CRP levels and exercise tolerance.