Albumin-based nutritional-inflammatory indices and prognosis in critically ill patients with acute myocardial infarction: a MIMIC-IV cohort study

This study investigated the associations between 12 albumin-based nutritional–inflammatory indices and adverse outcomes in critically ill patients with acute myocardial infarction and compared their prognostic performance. A retrospective cohort study was conducted using the MIMIC-IV database, which includes data from 2,255 critically ill AMI patients. Twelve nutritional and inflammatory indices were assessed: Advanced Lung Cancer Inflammation Index (ALI), Blood Urea Nitrogen to Albumin Ratio (BAR), Creatinine to Albumin Ratio (CAR), Controlling Nutritional Status (CONUT) score, Geriatric Nutritional Risk Index (GNRI), Hemoglobin-Albumin-Lymphocyte-Platelet (HALP) score, Lactate to Albumin Ratio (LAR), Monocyte to Albumin Ratio (MAR), Neutrophil to Albumin Ratio (NAR), Neutrophil Percentage to Albumin Ratio (NPAR), Prognostic Nutritional Index (PNI), and Red Cell Distribution Width to Albumin Ratio (RAR). The primary outcomes were 30-day and 365-day all-cause mortality (ACM), while secondary outcomes included new-onset atrial fibrillation (NOAF), new-onset ventricular arrhythmia (NOVA), and acute heart failure (AHF). In fully adjusted models, lower levels of GNRI, HALP, and PNI, and higher levels of BAR, CAR, CONUT, LAR, NPAR, and RAR were independently associated with increased 30-day and 365-day ACM. Restricted cubic spline analyses revealed nonlinear relationships for several indices (ALI, BAR, CAR, LAR, PNI). Among the indices evaluated, LAR showed the highest discriminatory performance for 30-day all-cause mortality (AUC = 0.719), whereas BAR showed the highest discriminatory performance for 365-day all-cause mortality (AUC = 0.717). Incremental predictive analyses further supported the additional prognostic information provided by these indices compared with albumin alone. Multiple nutritional indices were significantly associated with both NOAF and NOVA during AMI hospitalization, whereas no significant associations were found with AHF or mechanical complications. However, the findings for mechanical complications should be interpreted cautiously because of the limited number of events. Albumin-based nutritional–inflammatory indices provide additional prognostic information in critically ill patients with acute myocardial infarction. LAR and BAR showed the greatest discriminatory performance for short- and long-term mortality, respectively, but should be considered adjunctive risk-stratification markers rather than stand-alone clinical decision tools.