Comparable renal effects of histidine-tryptophan-ketoglutarate and DelNido cardioplegia in a porcine model of cardiac arrest

Acute kidney injury (AKI) is a serious complication following on-pump cardiac surgery. Choosing the cardioplegic solution with the most appropriate myocardial protection and lowest grade of AKI could improve patient outcome. We compared the crystalloid histidine-tryptophan-ketoglutarate (HTK) solution and a Jonosteril®-based DelNido blood cardioplegic solution regarding AKI in a porcine model. Therefore, German landrace pigs (50–60kg) underwent median sternotomy, cardiopulmonary bypass at 34 °C and 90 min of cardiac arrest. Animals were randomized to single-shot cardioplegia of HTK (n = 9) or DelNido (n = 9) cardioplegic solution followed by 120 min of reperfusion. This study demonstrated that DelNido cardioplegia induced less hemoglobin (p < 0.01) and electrolyte imbalances of blood sodium, chloride, and calcium levels (all p < 0.01) after aortic cross-clamp than HTK cardioplegia. Renal biopsy analysis after 120 min of reperfusion revealed that histomorphological changes, oxidative and nitrosative stress as well as the cytosolic release of pro-apoptotic molecules in different nephron structures were comparable in HTK and DelNido cardioplegia. The comparability of both cardioplegic solutions was supported by measurements of the urine AKI biomarkers of L-type fatty acid-binding protein 1 (p = 0.38), neutrophil gelatinase-associated lipocalin (p = 0.34), and cystatin C (p = 0.46), which could not detect any differences between the groups. This large animal study demonstrated superiority of the DelNido solution regarding hemoglobin and blood electrolyte concentrations, but comparability of the HTK and DelNido blood cardioplegic solution regarding AKI for surgical interventions requiring cardiac arrest of 90 min. Patients with a higher risk for adverse events, due to either complex, prolonged surgery or a multitude of comorbidities, could especially benefit from the more physiological arrest conditions with DelNido cardioplegia.