title: Biphasic response in number of stem cells and endothelial progenitor cells after left ventricular assist device implantation: A 6month follow-up.
abstract: BACKGROUND
  Continuous blood flow could have deleterious effects on endothelium and vascular health. This could have serious consequences in patients with heart failure treated with continuous flow left ventricular assist devices (LVAD). Therefore, we studied effect of LVAD on three circulating vascular biomarkers: stem cells (SC), endothelial progenitor cells (EPC) and microparticles (MP).
  
  
  METHODS
  In 23 patients (5 women) with end-stage heart failure, SC, EPC and MP were measured before, and 3 and 6months after implantation of LVAD (HeartMate II). SC were defined using determination of surface antigen expression as mononuclear CD34+/CD45low+ cells and EPC as mononuclear CD34+/CD45low+/KDR+ cells. MP concentrations were determined by ELISA method.
  
  
  RESULTS
  Three months after LVAD implantation numbers of SC and EPC significantly decreased (p=0.01 and p=0.001, respectively). On the contrary, between 3rd and 6th month after implantation they significantly increased (p=0.006 and p=0.003, respectively).MP did not change significantly during the study despite exerting similar trend as SC and EPC.
  
  
  CONCLUSIONS
  Observed biphasic changes of SC and EPC might reflect two processes. First, shortly after LVAD implantation, improved tissue perfusion could lead to decrease in ischemic stimuli and ensuing decrease of SC and EPC. Second, continuous flow between 3rd and 6th month produced by LVAD could lead to increase of SC and EPC through activation of endothelium. This explanation could be supported also by similar trend in the changes of concentrations of MP.
authors.affiliation: Department of Cardiac Surgery, Institute of Clinical and Experimental Medicine, Prague, Czech Republic; Third Faculty of Medicine, Charles University, Prague, Czech Republic.
authors.forename: Peter
authors.initials: P
authors.lastname: Ivak
authors.affiliation: Laboratory for Atherosclerosis Research, Institute of Clinical and Experimental Medicine, Prague, Czech Republic; Department of Internal Medicine, 2(nd) Faculty of Medicine, Charles University in Prague, Czech Republic. Electronic address: japi@ikem.cz.
authors.forename: Jan
authors.initials: J
authors.lastname: Pitha
authors.affiliation: Laboratory for Atherosclerosis Research, Institute of Clinical and Experimental Medicine, Prague, Czech Republic; International Clinical Research Center, St. Anne's University Hospital, Brno, Czech Republic.
authors.forename: Peter
authors.initials: P
authors.lastname: Wohlfahrt
authors.affiliation: Laboratory for Atherosclerosis Research, Institute of Clinical and Experimental Medicine, Prague, Czech Republic.
authors.forename: Ivana
authors.initials: I
authors.lastname: Kralova Lesna
authors.affiliation: Laboratory for Atherosclerosis Research, Institute of Clinical and Experimental Medicine, Prague, Czech Republic.
authors.forename: Petr
authors.initials: P
authors.lastname: Stavek
authors.affiliation: Department of Cardiology, Institute of Clinical and Experimental Medicine, Prague, Czech Republic.
authors.forename: Vojtech
authors.initials: V
authors.lastname: Melenovsky
authors.affiliation: Department of Cardiology, Institute of Clinical and Experimental Medicine, Prague, Czech Republic.
authors.forename: Zora
authors.initials: Z
authors.lastname: Dorazilova
authors.affiliation: Department of Cardiology, Institute of Clinical and Experimental Medicine, Prague, Czech Republic.
authors.forename: Marketa
authors.initials: M
authors.lastname: Hegarova
authors.affiliation: Department of Cardiology, Institute of Clinical and Experimental Medicine, Prague, Czech Republic.
authors.forename: Jitka
authors.initials: J
authors.lastname: Stepankova
authors.affiliation: Department of Cardiac Surgery, Institute of Clinical and Experimental Medicine, Prague, Czech Republic.
authors.forename: Jiri
authors.initials: J
authors.lastname: Maly
authors.affiliation: Department of Clinical and Transplant Immunology, Institute for Clinical and Experimental Medicine, Prague, Czech Republic.
authors.forename: Alena
authors.initials: A
authors.lastname: Sekerkova
authors.affiliation: Department of Cardiac Surgery, Institute of Clinical and Experimental Medicine, Prague, Czech Republic.
authors.forename: Dominika
authors.initials: D
authors.lastname: Turcani
authors.affiliation: Department of Cardiac Surgery, Institute of Clinical and Experimental Medicine, Prague, Czech Republic; Second Department of Surgery, Department of Cardiovascular Surgery, First Faculty of Medicine, Charles University, Prague, Czech Republic.
authors.forename: Ivan
authors.initials: I
authors.lastname: Netuka
mesh_terms: D000328:Adult; D000368:Aged; D002452:Cell Count / Q000639:trends; D066026:Endothelial Progenitor Cells / Q000502:physiology*; D004730:Endothelium, Vascular / Q000166:cytology / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000097:blood / Q000503:physiopathology / Q000628:therapy*; D006352:Heart Ventricles; D006353:Heart-Assist Devices / Q000639:trends*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013234:Stem Cells / Q000502:physiology*; D013997:Time Factors; D055815:Young Adult
keywords: Endothelial progenitor cells; Microparticles; Stem cells; Vascular function; Ventricular assist device