Effects of myocardial postconditioning on the recruitment of endothelial progenitor cells.
BACKGROUND
Ischemic postconditioning (PostC), brief repetitive cycles of ischemia and reperfusion during early reperfusion, is suggested to protect the myocardium in patients with stent thrombosis-elevation myocardial infarction (STEMI) by improved endothelial dysfunction and alteration of cytokine release. These mechanisms are also of importance for the recruitment of endothelial progenitor cells (EPC), an endogenous repair mechanism for re-endothelialization and neoangiogenesis. The aim of this study was to investigate the effect of PostC on recruitment of EPC.


METHODS
EPC were analyzed in 20 patients with STEMI randomized to receive four cycles of PostC following percutaneous coronary intervention (PCI) or conventional PCI. Different subpopulations of EPC were quantified immediately and on day 4 using flow cytometry. Myocardium at risk, and infarct size was determined by cardiovascular magnetic resonance.


RESULTS
There was no influence of PostC on the number of different EPC (CD34(+) , CD133(+) , CD34(+) CD133(+) , CD34(+) KDR(+) , CD34(-) CD133(+) KDR(+) , CD34(+) CD133(+) KDR(+) ). Left ventricular ejection fraction, myocardium at risk, and infarct size did not correlate to the mobilization of EPC. There was an inverse correlation between the symptom-to-balloon time and the mobilization of progenitor precursor cells (CD34(+) cells: R =-0.527, P = 0.02; CD133(+) cells: R =-0.624, P = 0.004; CD34(+) CD133(+) cells: R =-0.466, P = 0.04).


CONCLUSIONS
Ischemic PostC did not result in improved mobilization of EPC in STEMI patients. The recruitment of progenitor cells seems to be related to the duration of ischemia rather than the size of the ischemic myocardial area. More effort is needed to understand the changes of endothelial surface markers by PostC and their role in EPC recruitment and homing.
Department of Medicine, Division of Cardiology, Karolinska Institutet, Stockholm, Sweden. christian.jung@ki.se
Christian
C
Jung
Peder
P
Sörensson
Nawsad
N
Saleh
Håkan
H
Arheden
Lars
L
Rydén
John
J
Pernow
D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D042783:Endothelial Cells; D005260:Female; D005434:Flow Cytometry; D019650:Hematopoietic Stem Cell Mobilization; D006801:Humans; D057775:Ischemic Postconditioning; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009206:Myocardium; D013234:Stem Cells