Low cardiac output syndrome (LCOS) is defined by an insufficient cardiac output to meet metabolic demands, leading to tissue hypoperfusion and potential organ dysfunction.¹ Although it affects up to 42% of neonates after cardiac surgery with cardiopulmonary bypass (CPB),² pharmacological prevention practices vary widely, with limited supporting evidence.^1,3,4 Surveys such as EuLoCOS-Paed in Europe and PCICS in North America have highlighted significant variability in LCOS prophylactic drug regimens.