Kinetics of plasma heat shock protein HSP-70 release in coronary artery surgery: on-pump versus off-pump

Abstract

Aim: Heat shock protein HSP-70 is known as protective chaperone molecule synthetized in response following ischemia and stress agents. It is detected in the myocardium and endothelium as well as in the circulation. Damaged as well as viable but exposed to stress cells contribute to the release of HSP-70 into the circulation. The aim of the study was to investigate if cardiopulmonary bypss (CPB) leads to more circulating HSP-70, on the basis of comparison dynamics of plasma concentration HSP-70 in 8 men undergoing procedures with the use of CPB (coronary artery bypass grafting, CABG group) and 8 men undergoing off-pump surgery (OPCAB group).

Methods: Blood samples were taken preoperatively, twice intraoperatively, immediately after surgical procedure (1 h) and 24-hours thereafter. The concentration of plasma HSP-70 was measured by means of immunoassay. The derived results were compared statistically with the frequency of incidence postoperative atrial fibrillation (AF).

Results: In CABG group was observed continuous gradual increase of plasma HSP-70 concentration during the operation with the peak 1 h after surgery (P<0.01), in striking contrast to OPCAB group, in which was detected small, but non statistically significant increase of HSP-70 1 h after operation. Significantly more of circulating HSP-70 it was detected in CABG group during the operation and 1 h after surgery (CABG vs OPCAB, respectively P<0.015 and P<0.028). In both groups among patients witch AF it was found higher postoperative values of circulating HSP-70 compared with the non-AF group (P=0.0415).

Conclusions: The use of CPB leads to significant more release of HSP-70 into the circulation. According to our findings high plasma concentration of HSP-70 may be the measure of operative cellular stress, ischemia or injury and may be related with greater onset of postoperative AF. High circulating HSP-70 levels is connected with higher incidence of postoperative AF after open heart surgery.