Impact of Valve Culture Positivity on Prognosis in Patients with Infective Endocarditis Who Underwent Valve Surgery

Introduction Infective endocarditis (IE) is a severe and fatal infection with high in-hospital and overall mortality rates of approximately up to 30%. Valve culture positivity was associated with in-hospital mortality and postoperative complications; however, few studies have analyzed the relationship between valve cultures and overall mortality over a long observation period. This study aimed to compare the association of valve culture positivity with overall mortality in patients with IE who underwent valve surgery. Methods A total of 416 IE patients admitted to a tertiary hospital in South Korea from November 2005 to August 2017 were retrospectively reviewed. A total of 202 IE patients who underwent valve surgery and valve culture were enrolled. The primary endpoint was long-term overall mortality. Kaplan-Meier curve and Cox proportional hazards model were used for survival analysis. Results The median follow-up duration was 63 (interquartile range, 38-104) months. Valve cultures were positive in 22 (10.9%) patients. The overall mortality rate was 15.8% (32/202) and was significantly higher in valve culture-positive patients (36.4%, p = 0.011). Positive valve culture [hazard ratio (HR) 3.921, p = 0.002], Charlson Comorbidity Index (HR 1.181, p = 0.004), Coagulase-negative staphylococci (HR 4.233, p = 0.001), new-onset central nervous system complications (HR 3.689, p < 0.001), and new-onset heart failure (HR 4.331, p = 0.001) were significant risk factors for overall mortality. Conclusions Valve culture positivity is a significant risk factor for long-term overall mortality in IE patients who underwent valve surgery. The importance of valve culture positivity needs to be re-evaluated, as the valve culture positivity rate increases with increasing early surgical intervention.