Prognostic Value of Inflammatory Indices in Patients with Infective Endocarditis: Peak C-Reactive Protein/Albumin Ratio as a Better Biomarker

OBJECTIVE
Infective endocarditis (IE) is a severe and potentially fatal infection associated with significant morbidity and mortality. Early identification of patients at high risk of adverse outcomes is essential for improving clinical management and prognosis. This study aimed to evaluate the prognostic value of various inflammatory indices, with a particular focus on the peak C-reactive protein/albumin ratio (CAR), in predicting in-hospital mortality among IE patients.


METHOD
This retrospective, single-center study included IE patients admitted between June 2020 and June 2023. The primary outcome was in-hospital mortality. For all patients, inflammatory indices, including peak serum CAR levels, were calculated, and their association with mortality was assessed.


RESULTS
Of 165 patients, 62 (37.6%) experienced in-hospital mortality. Non-survivors had significantly higher peak CAR levels (8.1 vs. 5.0, P < 0.001) and elevated levels of other inflammatory indices compared to survivors. Peak CAR demonstrated the highest discriminatory ability for predicting in-hospital mortality, with an area under the curve (AUC) of 0.764, outperforming other indices. Multivariate analysis confirmed that peak CAR was an independent predictor of mortality (adjusted hazard ratio = 1.16, 95% confidence interval: 1.10-1.23, P < 0.001). Net reclassification improvement and integrated discrimination improvement analyses further supported the superior reclassification and discrimination capabilities of peak CAR.


CONCLUSION
Peak CAR is a significant prognostic marker for in-hospital mortality in IE patients compared to traditional inflammatory indices. Incorporating peak CAR into clinical practice may improve risk stratification and guide treatment decisions.