Exploring at the molecular level the effects of blood and blood-insulin cardioplegias used during open-heart surgeries on myocardial prevention.

Aim: The aim of this study was to measure the changes in the levels of soluble adhesion molecules involved in acute inflammation during ischemia-reperfusion in adults who underwent open-heart surgery using blood and blood-insulin cardioplegia and to examine the differences in tissue damage at the molecular level as a consequence of insulin's effect on myocardial energy metabolism.

Methods: Non diabetic 36 patients were enrolled. Blood cardioplegia was used at all cases; insulin and glucose were added at the study group. Blood samples were taken from the coronary sinus and the radial artery before cross-clamp (T1), at 1st (T2) and 30th(T3) minutes after reperfusion. Soluble intercellular adhesion molecules-1 (sICAM-1), soluble vascular adhesion molecules-1 (sVCAM-1), soluble platelet/endothelial cells adhesion marker-1 (sPECAM-1) and serum lactate levels were measured in these samples. Cardiac enzymes (CK-MB, troponin, and myoglobin) were measured at postoperative 1th, 8th and 16th hours. The total duration of mechanical ventilatory support during postoperative period, and the number of days in the intensive care unit and hospital were recorded.

Results: No significant differences were observed in sVCAM-1 levels in blood taken from the radial artery at T1, T2 and T3 in either group. There were significant increases between T1 and T3 and between T2 and T3 in samples obtained form the coronary sinus (P=0.000 and P=0.003, respectively). Significant increases in sPECAM-1 in samples obtained from both sites between T2 and T3 in both groups (P=0.000) were observed. These differences were similar in both groups. Troponin levels at 8th and 16th hours in the blood-insulin cardioplegia group were higher than the blood cardioplegia group (P=0.003 and P=0.032, respectively).

Conclusion: Supplementation of blood cardioplegia with insulin did not yield a significant improvement in adhesion molecules. Therefore, superiority of one cardioplegia over the other in delivering myocardial protection during open-heart surgery has not been shown.