title: Circulating Endothelial Progenitor Cells and Clinical Outcome in Patients with Aortic Stenosis.
abstract: BACKGROUND
  Aortic stenosis (AS) is the most common valvular disease. Endothelial progenitor cells (EPCs) have a role in the repair of endothelial surfaces after injury. Reduced numbers of EPCs are associated with endothelial dysfunction and adverse clinical events, suggesting that endothelial injury in the absence of sufficient repair by circulating EPCs promotes the progression of vascular and possibly valvular disorders. The aim of this study was to assess EPC number in patients with AS and to study the predictive value of their circulating levels on prognosis.
  
  
  METHODS
  The number of EPCs was determined by flow cytometry in 241 patients with AS and a control group of 73 pts. Thirty-eight, 52 and 151 patients had mild, moderate and severe AS, respectively. We evaluated the association between baseline levels of EPCs and death from cardiovascular causes during follow up.
  
  
  RESULTS
  EPC level was significantly higher in patients with AS compared to the control group (p = 0.017). Two hundred and three patients with moderate and severe AS were followed for a median of 20 months. One hundred and twenty patients underwent an intervention. Thirty four patients died during follow up, 20 patients died due to cardiac causes. Advanced age, the presence of coronary artery disease, AS severity index (combination of high NYHA class, smaller aortic valve area and elevated pulmonary artery pressure) and a low EPC number were predictors of cardiac death in the univariate analysis. Multivariate logistic regression model identified low EPCs number and AS severity index as associated with cardiac death during follow up (p = 0.026 and p = 0.037, respectively).
  
  
  CONCLUSIONS
  EPC number is increased in patients with AS. However, in patients with moderate or severe AS a relatively low number of EPCs is associated with cardiac death at follow up. These results may help to identify AS patients at increased cardiovascular risk.
authors.affiliation: The Heart Institute, Kaplan Medical Center, Rehovot, Israel, Affiliated to the Hebrew University and Hadassah Medical School, Jerusalem, Israel.
authors.forename: Sara
authors.initials: S
authors.lastname: Shimoni
authors.affiliation: The Heart Institute, Kaplan Medical Center, Rehovot, Israel, Affiliated to the Hebrew University and Hadassah Medical School, Jerusalem, Israel.
authors.forename: Iris
authors.initials: I
authors.lastname: Bar
authors.affiliation: The Heart Institute, Kaplan Medical Center, Rehovot, Israel, Affiliated to the Hebrew University and Hadassah Medical School, Jerusalem, Israel.
authors.forename: Valery
authors.initials: V
authors.lastname: Meledin
authors.affiliation: Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Estela
authors.initials: E
authors.lastname: Derazne
authors.affiliation: The Heart Institute, Kaplan Medical Center, Rehovot, Israel, Affiliated to the Hebrew University and Hadassah Medical School, Jerusalem, Israel.
authors.forename: Gera
authors.initials: G
authors.lastname: Gandelman
authors.affiliation: The Heart Institute, Kaplan Medical Center, Rehovot, Israel, Affiliated to the Hebrew University and Hadassah Medical School, Jerusalem, Israel.
authors.forename: Jacob
authors.initials: J
authors.lastname: George
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001024:Aortic Valve Stenosis / Q000097:blood* / Q000401:mortality / Q000601:surgery; D016022:Case-Control Studies; D002452:Cell Count; D018450:Disease Progression; D066026:Endothelial Progenitor Cells / Q000473:pathology*; D005260:Female; D019918:Heart Valve Prosthesis Implantation; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012307:Risk Factors