BACKGROUND: The Naples prognostic score (NPS), a novel nutritional and inflammatory index, holds great promise for predicting the prognosis of heart failure (HF), but research on its association with HF outcomes is limited. OBJECTIVE: To analyze the relationship between the NPS and the incidence rate and long-term prognosis of HF. METHODS: Participants from the National Health and Nutrition Examination Survey (NHANES) data were allocated into three groups (group 0 (the NPS=0), group 1-2 (the NPS=1-2), and group 3-4 (the NPS=3-4)) based on the NPS level. Regression analysis was conducted to examine the relationship between the NPS and HF prevalence, and ROC curve analysis was employed to determine the prediction accuracy. The Cox proportional hazards model and Kaplan-Meier survival curves analyzed mortality risk, with subgroup and sensitivity analyses for model stability. RESULTS: The study included 47,300 individuals (mean age 47.18 years
51.07% female
68.86% non-Hispanic white). The HF prevalence was 2.30% (95% CI: 1.66, 3.17). Among 1,581 HF patients, 851 all-cause deaths occurred during a median follow-up of 6.84 years. In groups 3-4, the risk of all-cause, cardiovascular, and cancer mortality was significantly higher (4.18, 4.89, and 16.93, respectively, all p <
0.05) compared to group 0. Furthermore, a significant difference was observed in the association between the NPS and cancer mortality across age subgroups (p <
0.05). In contrast, there was no significant interaction between the NPS and all-cause mortality or cardiovascular mortality in subgroup analyses. CONCLUSIONS: The NPS is a low-cost and easy-to-calculate prognostic score that helps predict the clinical course of patients with HF.