Research On The Effects Of Volume Unloading On Myocardial Cells And The Change Of The MiRNA With Left Ventricular Assist Device During The Early Stage Of Myocardial Infarction

Objective:Left ventricular assist device(LVAD) has been extensively applied to heart failure patients. However there are still controversies about that if LVAD should be applied to myocardial infarction patients. Therefore, we made, we investigated the changes of cardiomyocyte after LVAD unloading in a ovine model of acute myocardial infarction(AMI), in order to provide the evidence that LVAD can be used in acute myocardial infarction. Base on this Hypothesis, we want to find changes of miRNA through high-throughput sequencing technologies under the condition of large animal myocardial infarction and guide the direction of miRNA research of human myocardial infarction(AMI) in the future. Methods:Acute MI was established in six adult sheep by ligation of circumflex coronary artery. Three of them were mechanically unloaded with an continue-flow LVAD(FW-Ⅱ axial pump) with heart beating. The others without LVAD supporting served as control.Postoperative hour 12、24、36、48、72, CTn I and other routine serum items wereexamined to evaluate the damage of cardiomyocytes. After 72 hour, the hearts were harvested for histological examinations. TUNEL staining was performed to evaluate theapoptosis of cardiocyte. Then, Base on Pearson Correlation Coefficient, we evaluate the correlation between samples. we find changes of mi RNA through high-throughput. Results:There were differences between the two groups in CTn I value in each time point. Inflammatory cells infiltration was less both in the peri-infarction and infarction area of unloading group than those of the control. A large number of myocardial cells were in hibernation status. And the myocardial cell apoptosis was significantly lower than that of control(47.83±16.24%VS75.80±11.16%,P<0.05). By calculating Pearson Correlation Coefficient between samples, we believe experimental design is reasonable, samples are repeated up to standard, the result of Pearson Correlation Coefficient shows good correlation between the samples of the same kind. Through high-throughput sequencing technologies, we find the level of 35 known miRNAs and 370 unknown miRNAs are changed. Conclusion:Our results suggest that early assistance with an LVAD in AMI can maintain myocardial cells in hibernation status, and inhibit apoptosis and inflammatory cells infiltration. These may provide a good condition for myocardial infarction treatment. At the same time, bases on changes of mi RNAs, we can guide the direction of miRNA research of human myocardial infarction(AMI) in the future.