Gender Differences in Surgical Patients Suffering from Active Infective Endocarditis (AIE)

Objectives: Epidemiological studies demonstrated a gender related impact on AIE incidence. Data from animal studies suggested the protective effect of estrogen against endothelial cell damage. From clinical perspective, if AIE is present and surgery required, female gender seems to become an independent predictor for increased risk of early mortality. The aim of our prospective observational cohort study was to evaluate the impact of gender on presentation and outcome in AIE patients.

Methods: Between April 2013 to June 2017, eighty patients, in which AIE was diagnosed based on clinical and histopathological examination, underwent aortic valve replacement (50 men, 30 women) at University Munich and Leipzig Heart Centers. Valvular tissue was examined (immunohistochemistry, molecular biology and microbiology). Plasma concentration of inflammatory cytokines was analyzed by ELISA. Gendered statistical analysis with regard to pre-, peri and postoperative risk (EuroSCORE 2 and logistic EuroSCORE) and outcome was performed using SPSS based exact Fisher's test, Chi squared and independent student's t-tests, respectively (p-value < 0.05).

Results: Preoperative cardiogenic shock and preoperative neurologic dysfunction were pronounced among women (p = 0.037 and 0.013, respectively). Despite the fact, that major Duke’s criteria were not distinct between men and women, men mainly expressed aortic regurgitation (AR) I-II, women AR 0-I. There was a tendency of men showing more positive blood cultures (p = 0.070). Bacterial distribution among female and male patients is demonstrating a distinction: men most frequently suffered from Enterococcus faecalis and Staphylococcus aureus. Women were infected by S. aureus, Staphylococcus epidermidis and Streptococcus gallolyticus. Leucocytes and CRP were distributed equally; IL-6 as only inflammatory marker demonstrated a gender related distinction (p = 0.028). Risk stratification revealed a significantly higher risk for women (EuroSCORE 2, logistic EuroSCORE, risk of renal failure, risk of mortality and morbidity (single and as combined endpoint). Statistically important were longer hospital stay, higher rates of tracheotomy and newly developed neurologic dysfunction.

Conclusion: In case of AIE presence and necessity of surgery, women are disadvantaged: they presented with higher disease stage and more clinical symptoms. The estimated risk and comorbidities of women are significantly higher compared with men. Further investigations are currently underway.