Impact of depression on circulating endothelial progenitor cells in patients with acute coronary syndromes: a pilot study

Aims Depression has been identified as a risk factor for an adverse prognosis and reduced survival in patients with acute coronary syndrome (ACS). The number of endothelial progenitor cells (EPCs) is an independent predictor of clinical outcomes in patients with ACS. The aim of this study was to evaluate the impact of depression on EPC levels in patients with ACS. Methods Out of 74 ACS patients [23 non-ST-segment elevation myocardial infarction (NSTEMI), 48 STEMI], 36 had a diagnosis of major depressive episode (MDE) according to the Diagnostic and Statistical Manual of Mental Disorders 4th edition (DSM-IV) criteria at the time of the inclusion in the study. Control groups were as follows: 15 healthy individuals and 18 patients with current MDE without a history of cardiovascular diseases. EPCs were defined as CD34(+)CD133(+)KDR(+) and evaluated by flow cytometry. All patients underwent standardized cardiological and psychopathological evaluations. Parametric and nonparametric statistical tests were performed wherever appropriate. Results ACS patients with MDE showed a significant decrease in circulating EPC number compared with ACS patients without MDE (P < 0.001). The ACS study population was then subdivided into STEMI and NSTEMI groups, and within each group patients with MDE again showed a significant decrease in circulating CD34(+)CD133(+)KDR(+) EPCs compared with others (P <0.001). Conclusion We showed that ACS patients with MDE have a reduced number of circulating CD34(+)CD133(+)KDR(+) cells compared with ACS patients without MDE, suggesting that the presence of MDE reduces the response of bone marrow to acute ischemic events. Considering the reparative role of EPCs in ACS patients, we propose that patients with MDE might be protected less than patients without MDE.