Impact of Custodiol‐N cardioplegia on acute kidney injury after cardiopulmonary bypass

Myocardial protection during cardiopulmonary bypass (CPB) can be achieved using cardioplegic solutions. Although, acute kidney injury (AKI) is a common complication following CPB, the effects of cardioplegic solutions on AKI have rarely been investigated. Within this study, the effects of the cardioplegic solutions histidine-tryptophan-ketoglutarate (HTK; Custodiol) and HTK-N (Custodiol-N) on AKI in a large animal model were compared. Therefore, Landrace pigs underwent median sternotomy, CPB at 34 degrees C, 90 minutes of cardiac arrest and 120 minutes of reperfusion. Animals were randomized for single-shot cardioplegia with either HTK (n = 10) or HTK-N (n = 10). Renal biopsies and sera were analyzed to determine AKI biomarkers and apoptosis. Compared to HTK, HTK-N induced a decreased extent of proximal tubule swelling (48.3 +/- 1.6 microm vs 52.3 +/- 1.1 microm, P = .05) and decreased cytochrome c release (0.26 +/- 0.04 vs 0.46 +/- 0.08, P = .04) without reaching statistical significance due to Bonferroni correction. Comparing baseline and postreperfusion levels, the hemoglobin (Hb) and blood calcium levels were lower in HTK-N (Hbbaseline : 6.0 +/- 0.6 mmol/L, Hbreperfusion : 6.2 +/- 0.7 mmol/L, P = .12; Ca(2+) baseline : 1.36 +/- 0.05 mmol/L, Ca(2+) reperfusion : 1.28 +/- 0.05 mmol/L, P = .16) compared to the HTK group (Hbbaseline : 5.9 +/- 0.4 mmol/L, Hbreperfusion : 4.7 +/- 0.8 mmol/L, P < .01; Ca(2+) baseline : 1.34 +/- 0.07 mmol/L, Ca(2+) reperfusion : 1.24 +/- 0.06 mmol/L, P < .01). The present study showed that HTK-N could positively affect the kidney during CPB. Hb and calcium levels were stabilized. A statistical trend was found showing that AKI-related proximal tubule swelling and cytochrome c release were diminished.