Introduction Sex-dependent differences of infective endocarditis (IE) have been reported. Women suffer from IE less frequently than men and tend to present more severe manifestations. Our objective was to analyse the sex-based differences of IE in the clinical presentation, treatment, and prognosis.

Material and methods We analysed the sex differences in the clinical presentation, modality of treatment and prognosis of IE in a national-level multicentric cohort between 2008 and 2018. All data were prospectively recorded by the GAMES cohort (Spanish Collaboration on Endocarditis).

Results A total of 3451 patients were included, of whom 1105 were women (32.0%). Women were older than men (mean age, 68.4 vs 64.5). The most frequently affected valves were the aortic valve in men (50.6%) and mitral valve in women (48.7%). Staphylococcus aureus aetiology was more frequent in women (30.1% vs 23.1%; p<0.001).

Surgery was performed in 38.3% of women and 50% of men. After propensity score (PS) matching for age and estimated surgical risk (European System for Cardiac Operative Risk Evaluation II (EuroSCORE II)), the analysis of the matched cohorts revealed that women were less likely to undergo surgery (OR 0.74; 95% CI 0.59 to 0.91; p=0.05).

The observed overall in-hospital mortality was 32.8% in women and 25.7% in men (OR for the mortality of female sex 1.41; 95% CI 1.21 to 1.65; p<0.001). This statistical difference was not modified after adjusting for all possible confounders.

Conclusions Female sex was an independent factor related to mortality after adjusting for confounders. In addition, women were less frequently referred for surgical treatment.