Prognostic utility of the inflammatory burden index for early mortality prediction in heart failure: a retrospective cohort study using the MIMIC-IV database

Abstract

Background: Systemic inflammation a key factor in the progression of heart failure (HF). The inflammatory burden index (IBI) has prognostic value in different conditions; however, its impact on short-term mortality in patients with HF remains uncertain. This study aimed to assess the association between IBI and mortality risk in patients with HF. Methods: In this retrospective study, 600 patients with HF from the Medical Information Mart for Intensive Care IV database (2008–2022) were examined and divided into three groups according to the log-transformed IBI (LnIBI). The main outcome measured was 28-day mortality in the intensive care unit (ICU). We used multivariable Cox and logistic regression to assess the independent effect of LnIBI on mortality, after adjustment for confounders. The dose-response relationship was modeled using restricted cubic splines. Predictive performance was compared using receiver operating characteristic curves, and Kaplan-Meier analysis was used to assess survival differences;subgroup analyses were conducted. Results: The cohort included 342 males (57.0%), with a median age of 71.0 years. The 28-day ICU mortality rates were 17.2% (103/600). In adjusted models, higher LnIBI independently predicted an elevated risk (for example, 28-day mortality after ICU admission: Hazard ratio (HR): 1.24, 95% confidence interval (CI): 1.09–1.41, p = 0.001; highest versus lowest tertile: HR: 1.99, 95% CI: 1.20–3.29, p = 0.008). Restricted cubic splines confirmed the linear dose-response relationship. LnIBI showed a superior area under the curve compared with C-reactive protein (CRP) for most endpoints (for example, 0.643 versus 0.595 for 28-day mortality after ICU admission, p = 0.032). Kaplan-Meier curves indicated poorer survival in the higher LnIBI tertiles (p < 0.05). Conclusions: Elevated IBI is independently associated with increased short-term mortality risk in critically ill patients with HF, outperforming CRP in predictive accuracy.