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Blood cardioplegia reduces oxidant burden in the ischemic and reperfused human myocardium
D Lapenna1, A Mezzetti, S de Gioia
1Istituto di Fisiopatologia Medica, Universit' G. D'Annunzio, Facoltà di Medicina e Chirurgia, Chieti, Italy.
Insights
Cold blood cardioplegia offers superior myocardial protection during coronary artery bypass grafting compared to cold crystalloid cardioplegia. Blood cardioplegia reduces oxidative stress and lipid peroxidation, preserving antioxidant defenses in the heart tissue.
Area of Science:
- Cardiology
- Biochemistry
- Cardiothoracic Surgery
Background:
- Myocardial protection during cardiac surgery is crucial.
- Oxidative stress contributes to ischemia-reperfusion injury.
- Different cardioplegia solutions may impact myocardial antioxidant capacity.
Purpose of the Study:
- To compare the effects of cold crystalloid versus cold blood cardioplegia on myocardial antioxidant defenses.
- To assess lipid peroxidation and glutathione-related parameters in atrial myocardium.
- To evaluate the impact on myocardial injury markers post-coronary artery bypass grafting.
Main Methods:
- 20 patients undergoing elective coronary artery bypass grafting were studied.
- 10 patients received cold crystalloid cardioplegia, 10 received cold blood cardioplegia.
- Atrial myocardium was analyzed for glutathione-related antioxidant defenses and lipid peroxidation.
Main Results:
- Both cardioplegia types increased lipid peroxidation and decreased nonprotein thiols post-ischemia/reperfusion.
- Cold blood cardioplegia resulted in lower lipid peroxidation and higher nonprotein thiols than crystalloid.
- Cold blood cardioplegia showed no significant glutathione transferase activation, unlike crystalloid.
- Higher postoperative creatine kinase levels were observed in the crystalloid group.
Conclusions:
- Cold blood cardioplegia provides superior protection to the ischemic and reperfused human myocardium.
- This protection is mediated, in part, by enhanced antioxidant mechanisms.
- Erythrocyte and plasma antioxidant capacity likely contribute to the benefits of blood cardioplegia.
Abstract:
In 20 patients receiving cold crystalloid cardioplegia (n = 10) or cold blood cardioplegia (n = 10) during elective coronary artery bypass grafting, the atrial myocardium was tested for glutathione-related antioxidant defenses and lipid peroxidation. In both groups, ischemia and reperfusion induced a significant increase in lipid peroxidation values (p < 0.05) that was associated with a depression of nonprotein thiol compound levels (p < 0.05). Compared with the cold crystalloid cardioplegia-treated patients, the cold blood cardioplegia-treated patients showed a lower lipid peroxidation (p < 0.05) and higher values of nonprotein thiol compounds (p < 0.05). Moreover, a significant ischemia and reperfusion-dependent activation of glutathione transferase was observed only in the cold crystalloid cardioplegia-treated patients. Selenium-dependent glutathione peroxidase and glutathione reductase activities did not change after release of the aortic cross-clamp and did not differ between the two groups. The highest postoperative plasma level of the myocardial-specific isoenzyme of creatine kinase was significantly more elevated in the cold crystalloid cardioplegia patients. Overall, these tissue biochemical features indicate a lower oxidant burden in the myocardium of cold blood cardioplegia-treated patients, a finding suggesting superior protection for the ischemic and reperfused human myocardium also through antioxidant-type mechanisms, apparently medicated by the antioxidant capacity of erythrocytes and specific plasma molecules.