Cardioplegia modalities and systemic redox status in younger vs. older patients undergoing cardiac surgery

Patients undergoing cardiac surgery frequently suffer impaired myocardial redox protection during cardiopulmonary bypass (CPB), with elderly patients facing higher complication risks. We investigated the redox-protective effects of blood versus del Nido cardioplegia on systemic redox homeostasis, stratified by age, in patients undergoing coronary bypass and isolated valve surgery.

Systemic redox biomarkers were assessed with immunochemical and spectrophotometric methods in patients stratified by cardioplegia type (blood vs. del Nido) and age (< 60 vs. ≥60 years). Redox biomarkers such as MnSOD, catalase, total thiol, PCO, AOPP, LOOH, GPxA, and AGE were analyzed in blood samples of postoperative CPB patients (n = 60).

MnSOD levels were significantly higher with blood cardioplegia, indicating increased mitochondrial oxidative stress, whereas lower levels in the del Nido group suggested improved redox balance. Catalase activity appeared higher in the del Nido group, potentially influenced by outliers. Total thiol levels varied significantly among younger patients: those receiving blood cardioplegia had higher thiol concentrations, suggesting a more robust antioxidant buffer. No significant differences were observed regarding PCO, AOPP, LOOH, GPxA, or AGE between groups.

This analysis highlights MnSOD as the most reliable biomarker for differentiating cardioplegia strategies. Lower MnSOD levels in the del Nido group support its superior redox-protective effects, which are particularly relevant for reducing surgical complications in elderly patients undergoing cardiac surgery.