Impact and associated factors of staphylococcus aureus aggressiveness in patients with infective endocarditis

Introduction Infective endocarditis caused by Staphylococcus aureus (SA) is a severe infection associated with high morbidity and mortality. This study analyzes its temporal trend, clinical characteristics, and factors associated with poor prognosis in a cohort of patients from 2016 to 2024. Methods This is a retrospective study of 234 patients with infective endocarditis between 2016 and 2024. Clinical characteristics, complications, and outcomes of patients infected with SA were analyzed and compared with those infected by other microorganisms. Chi-square tests were used for categorical variables and Student’s t-test for continuous variables. A multivariate analysis was performed to identify independent factors associated with mortality. Results The temporal trend of SA did not show a significant increase (p = 0.907). Staphylococcus aureus accounted for 17.9% of endocarditis cases. SA-infected patients more frequently had infections in native valves (84.6%) compared to infections by other microorganisms, which primarily affected prosthetic valves (p = 0.003). SA infection was associated with higher mortality (45.2%, p = 0.022) and more complications (73.8%). The presence of shock was significantly associated with increased mortality (78.6% vs. 28.6%, p = 0.006), while valve type (native vs. prosthetic) was not significantly associated with mortality (p = 0.139). Patients who underwent surgery had lower mortality (26.7% vs. 55.6%), although this did not reach statistical significance (p = 0.139). Other complications (valvular dysfunction, stroke, AV block, embolism) were not significantly associated with mortality. Conclusion Staphylococcus aureus is associated with higher mortality and complications in infective endocarditis. Its aggressiveness is reflected in its strong association with shock and its high mortality, regardless of valve type. Surgery showed a trend toward reduced mortality, although without statistical significance. Early identification and appropriate management of these cases are essential to improve outcomes.