Peter Ivak1, Jan Pitha2, Peter Wohlfahrt3, Ivana Kralova Lesna4, Petr Stavek4, Vojtech Melenovsky5, Zora Dorazilova5, Marketa Hegarova5, Jitka Stepankova5, Jiri Maly6, Alena Sekerkova7, Dominika Turcani6, Ivan Netuka8. 1. Department of Cardiac Surgery, Institute of Clinical and Experimental Medicine, Prague, Czech Republic; Third Faculty of Medicine, Charles University, Prague, Czech Republic. 2. 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. 3. 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. 4. Laboratory for Atherosclerosis Research, Institute of Clinical and Experimental Medicine, Prague, Czech Republic. 5. Department of Cardiology, Institute of Clinical and Experimental Medicine, Prague, Czech Republic. 6. Department of Cardiac Surgery, Institute of Clinical and Experimental Medicine, Prague, Czech Republic. 7. Department of Clinical and Transplant Immunology, Institute for Clinical and Experimental Medicine, Prague, Czech Republic. 8. 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.
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.
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.