Infective endocarditis (IE) is a severe disease associated with significant morbidity and mortality despite advances in antimicrobial therapy and cardiac surgery. In complicated cases, surgical intervention is frequently required.

This retrospective observational study aims to evaluate outcomes in adult patients undergoing cardiac surgery for infective endocarditis at the Azienda Ospedaliero-Universitaria SS. Antonio e Biagio e Cesare Arrigo of Alessandria. The primary objective is to assess 30-day mortality after surgery and to analyze clinical and surgical factors associated with adverse outcomes.

Secondary objectives include the description of epidemiological, clinical, microbiological, and therapeutic characteristics of surgically treated infective endocarditis, the identification of predictors of postoperative complications, and the evaluation of mortality and recurrence of infection at 6 and 12 months after surgery. The study also assesses the consistency between documented surgical indications and the recommendations of the European Society of Cardiology (ESC) guidelines for the management of infective endocarditis.

Infective endocarditis (IE) remains a severe disease associated with high morbidity and mortality despite advances in antimicrobial therapy and cardiac surgery. Surgical treatment is often required in complicated cases, such as severe valvular dysfunction, uncontrolled infection, or high embolic risk.

IE is characterized by the formation of vegetations, defined as pathological masses composed of fibrin, platelets, white blood cells, and microorganisms. These lesions mainly involve native or prosthetic cardiac valves but may occasionally develop on other endocardial devices.The microorganisms most frequently responsible for complicated forms of infective endocarditis are typically aggressive pathogens or organisms with resistance to antimicrobial therapy. In recent years, the incidence of infective endocarditis appears to show a continuous increasing trend. This increase may be related to several factors, including the aging of the population, the growing use of implantable cardiac devices, and changes in antibiotic prophylaxis strategies. These epidemiological changes highlight the need for continuous evaluation and improvement of diagnostic and therapeutic strategies for a disease that remains associated with substantial morbidity and mortality.

This retrospective observational study includes all adult patients who underwent cardiac surgery for infective endocarditis between 2019 and 2024 at the University Hospital of Alessandria. The diagnosis of infective endocarditis is defined according to the modified Duke criteria and is retrospectively confirmed based on the available clinical documentation.

The study also evaluates the consistency between documented surgical indications and the recommendations of the current European Society of Cardiology (ESC) guidelines for the management of infective endocarditis.

Inclusion Criteria:

• Age ≥ 18
• Patients admitted to the AOU AL and undergoing surgery between 2019 and 2024 for infectious endocarditis with ICD-9 diagnosis:

O 4210 -Acute and subacute bacterial endocarditis O 4211-Acute and subacute infectious endocarditis in diseases Classified elsewhere O 4219 -Unspecified acute endocarditis O 42490 -Endocarditis, unspecified valve, specify Specified O 42491 -Endocarditis in diseases classified elsewhere O 42499 -Other endocarditis, valves not specified

- Signature of informed consent

Exclusion Criteria:

• Incomplete medical records or records with data missing that is relevant to this study
• Severely immunocompromised patients (e.g. organ transplant patients, patients undergoing intensive chemotherapy, patients with advanced AIDS, etc.)

Patients who underwent surgery for infective endocarditis between 2019 and 2024