Outcome parameters

The primary outcome of this trial was early post‐operative haemodynamic instability quantified by the vasoactive‐inotropic score (VIS), frequency of VS and length of vasopressor need. VIS was calculated according to the formula: VIS = dopamine dose (μg/kg/min) + dobutamine dose (μg/kg/min) + 100× adrenaline dose (μg/kg/min) + 10× phosphodiesterase inhibitor dose (μg/kg/min) + 100× noradrenaline dose (μg/kg/min) + 10 000× vasopressin dose (U/kg/min) ¹⁸ based on the mean doses in the post‐operative first 24 h for each agent. VIS was considered as ‘high’ if values ≥30 points, representing a higher risk for unfavourable outcomes. ¹⁹ Quantitative criteria of VS were mean noradrenaline requirements ≥0.3 μg/kg/min and need for argipressin supplementation at any dose to achieve a MAP >60 mmHg assessed over the first 24 h.

Secondary outcome parameters were defined as the inflammatory response characterized by a 72‐h change in procalcitonin (PCT) and C‐reactive protein (CRP) levels; duration of MV; surgery associated bleeding and reoperation for bleeding; frequency and severity of acute kidney injury (AKI) classified by applying the KDIGO creatinine‐based definition criteria for the first 5 post‐operative days ²⁰ ; 24‐h per cent change in bilirubin level using the equation: PCB = ([post‐CPB 24‐h bilirubin level (mg/dL)] − [pre‐operative bilirubin level (mg/dL)]/[pre‐operative bilirubin level (mg/dL)]) × 100, frequency of early sepsis screened for in the first 5 post‐operative days; length of ICU and hospital stay; intraoperative change in MPA plasma concentration; early allograft rejection; 30‐day mortality rate and 1‐year survival. Biomarkers of inflammatory response and creatinine clearance as well as the total bilirubin serum concentration were quantified from venous blood samples collected at designated time points using standard validated laboratory measurements.