Etiology, Risk Factors and Clinical Outcomes in Infective Endocarditis Patients Requiring Cardiac Surgery

Background: Infective endocarditis, which may be caused by various microbial agents, severely affects the innermost layer of the heart and often leads to poor clinical outcomes. The purpose of this study was to investigate the etiology, risk factors and short and long-term outcomes of infective endocarditis caused by various bacterial agents in patients requiring cardiac surgery. Methods: One hundred and forty-four patients aged 18 years or above with indications for cardiac surgery due to S. aureus, Streptococcus spp., E. faecalis or coagulase-negative staphylococci caused infective endocarditis were included in this study. Results: S. aureus, Streptococcus spp., E. faecalis and coagulase-negative staphylococci were the causative agents of infective endocarditis in 44 (30.6%), 35 (24.3%), 33 (22.9%) and 32 (22.2%) patients, respectively. The presence of bicuspid aortic valve was the most common predisposing factor confirmed in 19 (23.5%), whereas intravenous drug usage was the most common in 17 (11.8%) patients. No significant differences in intrahospital mortality due to infective endocarditis caused by various bacterial agents were found, however, the worsening of long-term prognosis of endocarditis caused by S. aureus when compared to E. faecalis was confirmed (p = 0.03). The presence of S. aureus was associated with significantly higher rates of embolic complications (p = 0.003). The presence of coagulase-negative staphylococci was associated with prosthetic valve endocarditis (p = 0.015) and perivalvular complications (p = 0.024). Conclusions: In contrast to E. faecalis, the presence of S. aureus determines the worsening of the long-term mortality from infective endocarditis. Perivalvular complications are associated with the presence of coagulase-negative staphylococci.