Association of the prognostic nutritional index with in-hospital adverse cardiovascular events among emergency department patients with acute heart failure

Background Acute heart failure (AHF) is prone to early clinical deterioration. The prognostic nutritional index (PNI), derived from serum albumin and lymphocyte count, is readily available. We evaluated the association of early PNI with incident in-hospital adverse cardiovascular events and its incremental prognostic value. Methods This retrospective cohort included consecutive adults presenting to the emergency department with AHF from March 2022 through March 2026. PNI was calculated from measurements obtained within 24 h and classified as low (<45) or high (≥45). The primary outcome was a post-index composite of all-cause death, cardiogenic shock, sustained ventricular arrhythmia, cardiac arrest, acute myocardial infarction, or worsening AHF requiring treatment escalation. Multivariable logistic regression evaluated associations; missing covariates were handled using multiple imputation. Discrimination was quantified by the area under the receiver operating characteristic curve (AUC). Results Of 367 patients (156 low PNI; 211 high PNI), 112 (30.5%) experienced the primary outcome. Events occurred in 43.6% and 20.9%, respectively ( P < 0.001). After adjustment, low PNI remained associated with higher odds of the primary outcome (odds ratio [OR], 1.92; 95% confidence interval [CI], 1.10–3.35; P = 0.022). Each 5-point PNI increase was associated with lower odds (OR, 0.70; 95% CI, 0.56–0.90; P = 0.003). PNI alone yielded an AUC of 0.714. Adding PNI increased the conventional model AUC from 0.776 to 0.829 (increase, 0.053; 95% CI, 0.021–0.085; P = 0.001); bootstrap-corrected AUCs were 0.752 and 0.803, respectively. Conclusions Low PNI was associated with higher adjusted odds of in-hospital adverse cardiovascular events. PNI provided modest incremental prognostic information and may serve as a complementary marker for early risk stratification.