Level and value of circulating endothelial progenitor cells in patients with acute myocardial infarction undergoing primary coronary angioplasty: in vivo and in vitro studies

Levels of circulating endothelial progenitor cells (EPCs) in acute ST-elevation myocardial infarction (STEMI) patients undergoing primary coronary intervention (PCI) were investigated in this study. Flow cytometric analysis of the circulating EPC level (CD31/CD34 [E₁], CD62E/CD34 [E₂], and KDR/CD34 [E₃]) was determined from blood samples of 161 consecutive patients with STEMI undergoing primary PCI. Angiogenesis was evaluated using mononuclear cell-derived EPCs on Matrigel. The EPC number (E_1–3) was lower in STEMI patients than in normal subjects (n = 25) (P < 0.005). Patients with high EPCs (E_1–3) (≥1.2%) had a lower left ventricular ejection fraction, elevated white blood cell count and creatinine level, advanced Killip score (≥class 3), more advanced congestive heart failure (CHF) (≥class 3), and increased 30-day mortality than those with a low EPC (E_1–3) level (<1.2%) (P < 0.0001). Angiogenesis was lower in patients with a high EPC level than those with a low EPC level and normal controls (P < 0.001). Both the advanced Killip score and the CHF were independent predictors of increased EPC levels (P < 0.05). Multivariate analysis identified a high EPC (E₃) level to be the most important predictor of increased 30-day major adverse clinical outcome (MACO) (P < 0.0001). In conclusion, the circulating EPC level is a major independent predictor of 30-day MACO in patients with STEMI undergoing primary PCI.

Abbreviations: 2-D, 2-dimensional, AMI, acute myocardial infarction, BrdU, 5-bromodeoxyuridine, CHF, congestive heart failure, CI, confidence interval, CK-MB, creatine kinase, EC, endothelial cell, EPC, endothelial progenitor cell, FBS, fetal bovine serum, FITC, fluorescein isothiocyanate, KDR, kinase insert domain-conjugating receptor, LV, left ventricular, LVEF, left ventricular ejection fraction, MACO, major adverse clinical outcome, MI, myocardial infarction, MNC, mononuclear cell, OR, odds ratio, PCI, percutaneous coronary intervention, PE, phycoerythrin, SD, standard deviation, STEMI, ST-elevation myocardial infarction, TIMI, thrombolysis in myocardial infarction, VEGF, vascular endothelial growth factor, WBC, white blood cell