Myocardial creatine kinase expression after left ventricular assist device support.
OBJECTIVE
We examined whether unloading of the left ventricle with a ventricular assist device (LVAD) can result in normalization of the creatine kinase (CK) abnormalities in the failing human heart.


BACKGROUND
Left ventricular failure is associated with a decrease of myocardial total CK activity and a fetal shift in CK isoform expression that results in an increase in the cytosolic brain type homodimeric-creatine kinase (CK-B) subunit and decreases of the cytosolic muscle-creatine kinase (CK-M) and CK-mitochondrial (CK-Mt) isoforms. The mechanisms of this abnormality are not known.


METHODS
Total CK activity and CK protein isoform expression (Western blotting) were examined in 11 patients with end-stage cardiomyopathy. In 7 patients, myocardial tissue was also obtained after 4.1 +/- 1.1 months of left ventricular assist device (LVAD) support.


RESULTS
Left ventricular unloading produced by LVAD implantation resulted in a 270% +/- 114% increase in total CK activity (p < 0.01) that was associated with a 69% +/- 18% increase in CK-M protein expression (p < 0.01) and a 121% +/- 69% increase in CK-Mt protein expression (p < 0.01), but no significant change in CK-B expression.


CONCLUSIONS
Systolic and diastolic unloading provided by the LVAD resulted in increases of total CK activity as well as CK-Mt and CK-M protein expression. The failure of CK-B expression to decrease suggests that abnormalities other than increased loading are responsible for the increase in CK-B expression in the failing heart.
Park
Soon J
SJ
Department of Surgery, University of Minnesota, 420 Delaware Street SE, Minneapolis, MN 55455, USA.
Zhang
Jianyi
J
Ye
Yun
Y
Ormaza
Sofia
S
Liang
Peihua
P
Bank
Alan J
AJ
Miller
Leslie W
LW
Bache
Robert J
RJ
D000328:Adult; D015153:Blotting, Western; D002311:Cardiomyopathy, Dilated / Q000378:metabolism; D003402:Creatine Kinase / Q000378:metabolism*; D006333:Heart Failure / Q000378:metabolism*; D006353:Heart-Assist Devices; D006801:Humans; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism*; D020033:Protein Isoforms / Q000378:metabolism
D020033:Protein Isoforms; D003402:Creatine Kinase