Association between lactate/albumin ratio and prognosis in patients with acute myocardial infarction.

Background: The association between the lactate/albumin ratio (L/A) as a diagnostic indicator and unfavourable clinical outcomes has been established in patients with community-acquired pneumonia, sepsis and heart failure, but the connection between L/A and all-cause mortality in patients with acute myocardial infarction (AMI) has yet to be fully understood.

Methods: This was a retrospective cohort study using MIMIC-IV (v2.2) data, with 2816 patients enrolled and all-cause mortality during hospitalization as the primary outcome. Kaplan-Meier (KM) analysis was used to compare the all-cause mortality between high-level and low-level L/A groups. Receiver operating characteristic (ROC) curve, Restricted cubic splines (RCS) and Cox proportional hazards analysis were performed to investigate the relationship between L/A ratio and in-hospital all-cause mortality.

Results: L/A values were significantly higher in the non-survivor groups than the survival groups (1.14 [.20] vs. .60 [.36], p < .05), and area under the ROC curve [.734 (95% confidence interval, .694-.775)] was better than other indicators. Data of COX regression analysis showed that higher L/A value supposed to be an independent risk factor for in-hospital mortality. RCS analysis showed evidence of an increasing trend and a non-linear relationship between L/A and in-hospital mortality (p-value was non-linear <.05). KM survival curves were significantly lower in the high L/A group than the low L/A group (p < .001), and the former group had an increased risk of in-hospital mortality compared with the latter one (Log Rank p < .001).

Conclusions: L/A demonstrates significant independent predictive power for elevated all-cause mortality during hospitalization in patients diagnosed with AMI.