Differential Associations of Neutrophil-To-Lymphocyte Ratio, Systemic Immune-Inflammation Index, and Serum Albumin with In-Hospital Mortality and Prolonged Length of Stay Among Patients with Heart Failure

Abstract

Heart failure (HF) involves inflammatory and systemic disturbances that may influence short-term hospital outcomes. This retrospective cohort study examined the associations of neutrophil-to-lymphocyte ratio (NLR), systemic immune-inflammation index (SII), and serum albumin with in-hospital mortality and prolonged length of stay (LOS) among 147 adults hospitalized with HF. Admission complete blood counts were used to calculate NLR and SII, while serum albumin was obtained at admission or within 24–48 hours. Eight patients (5.4%) died and 38 (25.9%) had prolonged LOS (≥9 days). Median NLR and SII were higher in patients who died than in survivors (16.97 vs 3.32 and 3,617.50 vs 790.00, respectively; both p<0.001), whereas albumin did not differ significantly (p=0.100). NLR and SII yielded mortality AUCs of 0.942 and 0.895, respectively; the combined NLR–SII–albumin model yielded an AUC of 0.946. For prolonged LOS, albumin was lower in affected patients (3.30 vs 3.60 g/dL; p=0.001), correlated inversely with numerical LOS (rₛ=−0.220; p=0.007), and remained independently associated after adjustment (adjusted OR 0.230; 95% CI 0.104–0.511). Albumin showed the strongest individual discrimination for prolonged LOS (AUC 0.675). NLR and SII were more closely related to in-hospital mortality, whereas albumin was more consistently related to prolonged hospitalization. These findings, particularly the mortality discrimination estimates, require external validation.