Neutrophil-to-Lymphocyte-to-Platelet Ratio Predicts Acute Kidney Injury in Critically Ill Heart Failure Patients

Acute kidney injury (AKI) is a frequent and lethal complication in critically ill patients with heart failure (HF), driven by complex interactions among hemodynamic instability, systemic inflammation, and immune dysregulation. The Neutrophil-to-Lymphocyte-to- Platelet Ratio (NLPR) is a novel composite biomarker integrating inflammatory and thrombotic pathways. This retrospective cohort study utilized data from the MIMIC-IV database to investigate the association between NLPR and AKI risk in critically ill HF patients. Among 3,942 patients, the overall AKI incidence was 86.53%. A graded, independent association was observed between elevated NLPR and AKI risk. In fully adjusted models, patients in the highest quartile had a 30% higher AKI risk compared to the lowest quartile (HR 1.30, 95% CI 1.17–1.44, P < 0.001). Restricted cubic spline analysis confirmed a non-linear dose-response relationship. Higher NLPR was also associated with advanced AKI stages, increased renal replacement therapy requirement, and poorer 30-day survival. As a readily available biomarker, elevated NLPR at ICU admission is independently associated with increased AKI risk and adverse outcomes, enhancing early risk stratification in this high-risk population.