INTRODUCTION: Lactate clearance(LC) is critical in managing critically ill patients. We hypothesized that treatment allocation with different vasoactive drugs or the presence of a pulmonary artery catheter (PAC) could affect the behavior of lactate dynamics and, ultimately, the mortality in AMI-CS. MATERIALS AND METHODS: In 651 patients with AMI-CS, we examined the relationship of LC time with clinical, laboratory, and CS-management variables. Complete LC time was defined as serum lactate levels less than <
2 mmol/L. We explore the impact of vasoactive drugs and PAC with LC. The CART method defined the vasoactive combinations (permutations) in relation with early (<
96 h) complete LC. RESULTS: PAC presence correlated with faster LC (-17.54 h) and was independently associated with lower mortality (HR = 0.61). Levosimendan and dobutamine were associated with lower lactate levels and faster LC (-8.82 & -8.77 h), while vasopressin was linked to slower LC (9.16 h). Slow LC (>
96 h) was associated with increased mortality. CART analysis identified specific vasoactive drug combinations associated lactate clearance and mortality, without dobutamine, with vasopressin having higher mortality (80.6 %, HR = 5.53), and with dobutamine, with norepinephrine, without vasopressin, with levosimendan the lowest (35 %) and higher complete LC and a trend for higher %LC. CONCLUSION: The right combination of vasoactive medications and the probable use of a PAC could significantly impact the achievement of complete LC in <
96 h. The findings support the need for further research and the development of strategies to optimize lactate clearance and improve overall patient survival in this high-risk population.