Redefining prognostic markers in infective endocarditis: the role of systemic inflammation and anemia

Background Risk stratification in infective endocarditis (IE) remains a major challenge, particularly among patients without surgical indication. Although several biomarkers and clinical variables have been proposed to estimate short-term risk, their prognostic relevance for long-term mortality is less well established. Purpose Identify independent predictors of in-hospital, 6-month, and 1-year all cause mortality, as well as a composite outcome including all-cause death at any time point, in a contemporary cohort of patients with IE. Methods Retrospective observational study including all patients hospitalized for definitive IE between 2017 and 2022 at a secondary cardiac center according to the modified Duke criteria. Logistic regression models were constructed for in-hospital mortality, 6-month mortality, 1-year mortality, and a composite endpoint including any death within 1 year. The following covariates were included in all models: peak procalcitonin (PCT max), minimum hemoglobin (Hb min), peak creatinine (Creat max), presence of acute kidney injury (LRA), infection by multidrug-resistant organisms (MR+), presence of local complications, body mass index (BMI), and age. Results In the multivariate model for in-hospital mortality, PCT max (OR 1.18, 95% CI 1.03–1.34, p = 0.018), Hb min (OR 0.35, 95% CI 0.13–0.93, p = 0.035), and MR+ (OR 57.5, 95% CI 1.6–2050, p = 0.041) were independently associated with death during admission. Other variables, including Creat max (p = 0.216), LRA (p = 0.621), local complications (p = 0.683), BMI (p = 0.105), and age (p = 0.296), were not statistically significant. For 6-month mortality, both PCT max (OR 1.12, 95% CI 1.01–1.25, p = 0.026) and Hb min (OR 0.43, 95% CI 0.20–0.93, p = 0.034) remained significant predictors. All other variables did not reach statistical significance. Similar findings were observed for 1-year mortality, where PCT max (OR 1.12, 95% CI 1.01–1.25, p = 0.028) and Hb min (OR 0.44, 95% CI 0.20–0.96, p = 0.038) were again independently associated with death. No significant effects were found for the other variables. When the composite outcome including all-cause death up to 1 year was analyzed, PCT max (OR 1.12, 95% CI 1.01–1.25, p = 0.026) and Hb min (OR 0.43, 95% CI 0.20–0.93, p = 0.034) persisted as the only significant predictors. Conclusions Across all time horizons, peak PCT and minimum hemoglobin emerged as consistent and independent predictors of mortality in IE, reflecting the combined impact of systemic inflammation and anemia on adverse prognosis. The presence of multidrug-resistant microorganisms was an additional significant and important determinant of in-hospital death. Other variables, including renal dysfunction, local complications, BMI, and age, showed no independent association with outcomes. These findings highlight the importance of integrating inflammatory and hematologic markers into prognostic assessment models for both surgical and non-surgical IE patients.