Abstract
BACKGROUND: Infective endocarditis (IE) remains a life-threatening condition despite treatment advances. Early identification of high-risk patients is essential. The neutrophil percentage-to-albumin ratio (NPAR) is a novel inflammatory marker linked to poor outcomes in various diseases, but its prognostic value in IE remains unclear. This study aimed to investigate the association between NPAR and in-hospital mortality in patients with IE. METHODS: We retrospectively analyzed 263 patients diagnosed with IE between January 2009 and January 2024 at a tertiary care center. Clinical, laboratory, and echocardiographic data were collected. NPAR was calculated as (Neutrophil %/Albumin [g/dL]). Predictors of mortality were identified using LASSO-based logistic regression, and a nomogram was constructed to illustrate predictive performance. RESULTS: In-hospital mortality occurred in 59 patients (22.4%). NPAR was significantly higher among non-survivors (median: 0.335 vs. 0.228, p < 0.001). High NPAR ( >0.274) was independently associated with in-hospital mortality (OR: 6.70, 95% CI: 3.07-15.61, p < 0.001), along with large vegetation and diabetes mellitus. High NPAR showed good discriminative power (AUC = 0.72, 95% CI: 0.66-0.79, p < 0.001). CONCLUSION: High NPAR was an independent predictor of in-hospital mortality in IE and may serve as a simple, cost-effective biomarker for early risk stratification.