Correlation Between Blood Culture Time to Positivity and Vegetation Size in Staphylococcus aureus Infective Endocarditis

<b>Background:</b> The relationship between vegetation characteristics in <i>Staphylococcus aureus</i> infective endocarditis (IE) and blood culture time to positivity (TTP) has not been investigated. This study evaluates the correlation between vegetation length and TTP in patients with <i>S. aureus</i> IE. <b>Methods:</b> A retrospective cohort study was conducted that included 164 definite cases <i>S. aureus</i> IE. Vegetation length was determined by transesophageal echocardiography (TEE), and TTP was measured in hours from the initial time of blood culture incubation to positivity. Correlations between vegetation characteristics and TTP were analyzed using Spearman's rank correlation coefficient. <b>Results:</b> A modest but statistically significant negative correlation was observed between vegetation length and TTP (Spearman ρ = -0.18, <i>p</i> = 0.020), suggesting that larger vegetations were associated with shorter TTP. No significant correlations were found for other vegetation characteristics (e.g., vegetation mobility, location, or number) and TTP. <b>Conclusions:</b> Larger vegetation size in <i>S. aureus</i> IE was associated with shorter TTP. These findings highlight the importance of vegetation size in the pathophysiology of <i>S. aureus</i> IE and its role in bacteremia dynamics.