The comparison of the effects of bretschneider htk and conventional crystalloid cardioplegia on myocardium at tissue level

Cardioplegic arrest is one of the most common myocardial protection strategies. A wide variety of cardioplegic solutions are routinely being used. There is an ongoing discussion about the relative effectiveness of these solutions considering myocardial protection. This study aims to investigate the hypothesis "The use of histidine-tryptophan-ketoglutarate (HTK) cardioplegia leads to decreased ischemic damage on myocardium compared with the use of conventional crystalloid cardioplegia." The study population was 32 patients operated in Başkent University Department of Cardiovascular Surgery for congenital heart diseases. The former 16 patients received conventional crystalloid cardioplegia (KK group) which is a modification of St. Thomas solution while the latter 16 patients received HTK solution (HTK group). The echocardiographic measurements and the laboratory values of the patients were taken as the clinical variables. Right ventricular biopsies were taken from every patient before and after cardioplegic arrest. These biopsies were histopathologically examined for apoptosis using caspase – 3 antigen and cell proliferation using Ki-67 antigen. The statistical analysis revealed no significant difference between the 2 groups regarding the clinical variables, apoptotic indices and proliferation indices. The apoptotic indices in the post-cardioplegic arrest biopsies were correlated with aortic clamp time in the KK group but not in the HTK group. Liver function tests on postoperative day 1 were positively correlated with aortic clamp time in both groups. On postoperative day 2 this correlation sustained in the KK group and ceased in HTK group. The difference in the correlation of apoptotic indices and liver function tests between the groups is accepted as a supportive finding for HTK solution. However it can be postulated that when the aortic clamp times are similar to those in the present study the clinical manifestation of the difference between the two solutions would not be significant.