Predictive value of the C-reactive protein-to-lymphocyte ratio for prognosis in heart failure patients with acute kidney injury.

BACKGROUND

The prognostic value of the C-reactive protein-to-lymphocyte ratio (CLR) in critical and inflammatory diseases is increasingly recognized. Nonetheless, its role in risk stratification for patients with congestive heart failure (CHF) who develop acute kidney injury (AKI) has not been thoroughly investigated. Research indicates that cardiorenal syndrome is mediated by a cytokine storm causing cardiac and renal injury, the extent of which can be quantified by the CLR and is significantly associated with adverse outcomes such as mortality and cardiovascular events. This study aims to elucidate the relationship between CLR and mortality in this patient population.

METHODS

Leveraging data from the MIMIC-IV database, we identified patients diagnosed with both CHF and AKI. We employed Cox models to gauge the link between CLR and near- and long-term (30-day/365-day) all-cause mortality, supplemented by Kaplan-Meier analysis across CLR quartiles. The non-linear dynamics of this relationship were mapped with restricted cubic splines (RCS). The model's predictive performance was appraised using ROC curves, and potential effect modifiers were probed through comprehensive subgroup analyses to elucidate the interplay of key factors.

RESULTS

Among 1605 patients, higher CLR quartiles were associated with significantly worse survival by Kaplan-Meier analysis (log-rank P < 0.001). After full multivariable adjustment, the risk of 365-day mortality increased progressively across CLR quartiles (Q2: HR 1.96 [1.33-2.90]; Q3: 2.19 [1.49-3.21]; Q4: 3.78 [2.63-5.43]; P-trend < 0.001). Similar trends were observed for 30-day mortality (Q4: 4.32 [2.19-8.53]; P-trend < 0.001), although the HRs for Q2 and Q3 did not reach statistical significance. Fully adjusted RCS confirmed linear LnCLR-mortality associations for 30-day (P for nonlinearity = 0.352) and 365-day outcomes (P for nonlinearity = 0.197). ROC analysis demonstrated fair discriminative ability of CLR for 30-day (AUC: 0.713) and 365-day mortality (AUC: 0.675). Subgroup analyses confirmed consistent prognostic effects (all P for interaction > 0.05).

CONCLUSION

CLR independently is associated with both short- and long-term mortality in CHF-AKI patients, supporting its clinical utility for risk stratification in this high-risk population.