OBJECTIVE- To measure plasma HSP70 concentration in cardiac surgical patients during preoperative, on Cardiopulmonary bypass and in postoperative periods to quantify the extent of cellular stress.

MATERIALS AND METHODS. A total of 60 cardiac patients undergoing revascularization or valve surgery on Cardiopulmonary bypass between July 2012 and Jan 2013, were included in the study after seeking approval by hospital ethical committee. Informed consent was taken from all enrolled patients.They were randomly divided and double blinded for intravenous administration of one gram of methylprednisolone (Group ‘M’) or no treatment group (Group ‘O’). Intra operative data includes total duration of surgery, cardiopulmonary bypass time, aortic cross clamping time. Four venous blood samples were taken, one before induction of anaesthesia, second sample on CPB (approx within half an hour), third sample after one hour of weaning from CPB and fourth sample on post operative day one i.e. at 24 hours.

The samples from group M (patients treated with methyl prednisolone) showed a significant increase in the expression of HSP70 in the samples which were taken after the initiation of CPB (HSP2) (p-value = 0.01) and in the sample drawn at one hour off CPB (HSP3). (p-value=0.02).However levels of HSP in group M and group O (patients not treated with Methylprednisolone) were similar at all time intervals during the study. Our study thus failed to show methyl prednisolone led to rise of HSP70.

RECOMMENDATIONS Our study finds that induction of CPB leads to expression of HSP70, and its levels are maximum at one hour post CPB and decreases by 24 hours. Administration of 1 gm of Methylprednisolone before induction of CPB doesn’t lead to any significant rise of HSP70 levels in peripheral blood. It is possible that peripheral blood levels do not correlate temporally and quantitatively with myocardial levels. To further evaluate the role of Methylprednisolone in myocardial protection in cardiopulmonary bypass; a study to validate the correlation of peripheral blood and myocardial HSP70 levels with and without Methylprednisolone is required. Also a further study to assess the effect of Methylprednisolone on clinical parameters and its correlation with HSP70 levels is required.