Remnant cholesterol inflammation index as a predictor of mortality in patients with acute decompensated heart failure: evidence from the Jiangxi, China cohort.

Introduction: The Remnant Cholesterol Inflammation Index (RCII) is a novel composite biomarker that integrates atherosclerotic and inflammatory statuses. The present study aimed to investigate the association between RCII and short-term prognosis in patients with acute decompensated heart failure (ADHF). Methods: A total of 1,055 ADHF patients enrolled in the Jiangxi-ADHF II cohort (2018-2024) were included. Multivariable Cox regression and restricted cubic spline analyses were used to assess the association between RCII and 30-day mortality in ADHF patients. Threshold analysis was performed to identify a potential inflection point. The DeLong test was applied to evaluate the incremental predictive value of RCII over RC and traditional lipid parameters. Furthermore, based on baseline characteristics, a baseline risk model for predicting short-term prognosis of ADHF was established, and the incremental predictive value of adding RCII to this model was evaluated. Mediation analysis examined the potential mediating effects of gamma-glutamyl transferase and albumin. Results: During the 30-day follow-up, 85 death events (8.06%) were recorded. After adjustment for multiple confounders, a higher RCII level was significantly associated with an increased risk of 30-day mortality in ADHF patients. Exploratory restricted cubic spline analysis further revealed an inverted L‑shaped dose-response relationship between LnRCII and 30‑day mortality ( Discussion: Our analysis identified a higher RCII as a significant predictor of increased short-term mortality in patients with ADHF, establishing RCII as a novel and important predictor of poor short-term prognosis in ADHF.