The burden of endocarditis has changed in the last years due to an increase in percutaneous valve procedures offered to a more fragile, and old population. Therefore an update in epidemiology data is necessary. The Observational prospective multicenter study to characterize the cLinical ANd DiagnoStiC feAtures of endocarditis in the contemPorary Era, (ENDO-LANDSCAPE study) is an observational, multicenter and international study. The study has two arms: retrospective and prospective.

The retrospective arm will involve collecting data from patients discharged with a diagnosis of endocarditis between 2016 and 2022. The data obtained in the retrospective arm of the study will be utilized in a power calculation to determine the sample size for the prospective arm of the study. In the prospective phase in every participating center, all patients referred for echocardiography to assess for endocarditis and those with established endocarditis independent of the screened request will be eligible. Patients will then be stratified according to the presence or abscence of endocarditis. Those with an established diagnosis of endocarditis will be prospectively followed for outcomes.

STUDY DESIGN The study will be multicenter and international with two arms: retrospective and prospective.

The retrospective arm will involve collecting data from patients discharged with a diagnosis of endocarditis between 2016 and 2022. The data obtained in the retrospective arm of the study will be utilized in a power calculation to determine the sample size for the prospective arm of the study.

Retrospective arm: It will be enrolled all patients discharged with a diagnosis of endocarditis. Data collected will be about: 1) position, size and type of valve or prosthesis infected, 2) echocardiographic data (both on transthoracic or transesophageal approach) regarding presence, size and morphology of vegetations and any other signs consistent with endocarditis (e.g.abscess, fistula, pseudoaneurysms), severity of valve disease; 3) imaging technique used for diagnosis in addition to echocardiography (computed tomography, positron emission computed tomography, single photon emission computed tomography); 4) management of the case performed by the endocarditis team (including cardiologist, microbiologist, cardiac surgeon, radiologist); 5) Duke criteria verification; 6) management of the case (conservative vs invasive); 7) antibiotic therapy prescribed and timing; 8) follow-up at one year (death, cardiac surgery, re-infection).

All data collected will be made anonymous. Data regarding follow-up will be obtained through medical chart or by hospital computer reporting systems. For this reason, a signed informed consent is not necessary for this phase of the study. All data will be collected in electronic format (e-CRF) on REDCAP.

Prospective arm: This phase will involve several international centres for a timeframe of 12 months.

All consecutive patients referred for a echocardiography with a suspicion of bacterial endocarditis and those with a confirmed diagnosis of endocarditis independently by the request will potentially be eligible for the study. Only the patients with a confirmed or with high suspicion of endocarditis will be prospectively followed for one year. As in the retrospective arm, these patients will be prospectively follow-up, and the following information collected: 1) type, size and position of infected valve or prosthesis, 2) echocardiographic data (both on transthoracic or transesophageal approaches) regarding presence, size and morphology of vegetations or other evidence of endocarditis (e.g. abscess, fistula, pseudoaneurysms), severity of valve disease; 3) imaging technique used for diagnosis in addition to echocardiography (computed tomography, positron emission computed tomography, single photon emission computed tomography); 4) management of the case performed by the endocarditis team (including cardiologist, microbiologist, cardiac surgeon, radiologist); 5) Duke criteria verification; 6) management of the case (conservative or invasive); 7) antibiotic therapy prescribed and timing; 8) follow-up at one year (death, cardiac surgery, re-infection).

For patients with no evidence of endocarditis on their echocardiogram, data on the following will be collected: i) size, type and position of valve prosthesis; ii) uke criteria verification.

In both cases a CRF will be filled. All patients enrolled in the prospective arm will sign a informed written consent.

Inclusion Criteria:

• Patients above the age of 18 years.
• all consecutive patients referred for echocardiography (transthoracic or transesophageal approach) to exclude endocarditis.
• patients with a diagnosis of endocarditis on echocardiography independently by the request for the exam.

Exclusion Criteria:

• patient's refusal.

All consecutive patients referred for a echocardiography with a suspicion of bacterial endocarditis and those with a confirmed diagnosis of endocarditis independently by the request will potentially be eligible for the study. Only the patients with a positive findings of endocarditis will be prospectively followed for one year. For patients with no evidence of endocarditis on their echocardiogram, data on the following will be collected: i) size, type and position of valve prosthesis; ii) Duke criteria verification.

upon reasonable request