Immune-Inflammatory markers and heart failure incidence and mortality: a population-based longitudinal study.

Background: Inflammation is a crucial pathophysiological driver contributing to the initiation and perpetuation of heart failure (HF). This study conducted a rigorous comparison among six immune-inflammatory indices to evaluate their predictive role for HF incidence and subsequent mortality. Methods: We analyzed data from 415,263 participants free of HF and 1,952 patients with established HF from the UK Biobank. The markers assessed were the systemic immune-inflammation index (SII), systemic inflammation response index (SIRI), aggregate index of systemic inflammation (AISI), inflammatory burden index (IBI), C-reactive protein-albumin-lymphocyte (CALLY) index, and neutrophil-to-lymphocyte ratio (NLR). The outcomes were incident HF and all-cause mortality among HF patients. Results: Elevated levels of SII, SIRI, AISI, IBI, and NLR showed significant, dose-response relationships with an enhanced likelihood of HF events. The IBI demonstrated the strongest association, with participants in the highest quintile having an 86% higher risk of HF than those in the lowest quintile (HR 1.86, 95% CI: 1.75-1.97). Conversely, a higher CALLY was associated with a lower risk of HF (HR for Q5 vs. Q1: 0.56, 95% CI: 0.53-0.60). Among HF patients, SIRI, AISI, IBI, and NLR had a positive correlation with all-cause mortality, whereas the CALLY was associated with improved survival (HR 0.81, 95% CI: 0.70-0.94). ROC analyses confirmed that IBI provided the superior predictive accuracy for both incident HF and mortality. Conclusion: Immune-inflammatory markers are significant predictors of HF incidence and prognosis. The IBI emerged as the most robust biomarker, underscoring its utility for risk stratification in primary and secondary HF prevention.