Epidemiology, characteristics, and outcome of infective endocarditis in Italy: the Italian Study on Endocarditis.

Background: The characteristics of patients with infective endocarditis (IE) vary significantly by region of the world. The aim of this study was to evaluate the contemporary epidemiology, characteristics, and outcome of IE in a large, nationwide cohort of Italian patients.
Methods: We conducted a prospective, observational study at 24 medical centers in Italy, including all the consecutive patients with a definite or possible diagnosis of IE (modified Duke criteria) admitted from January 2004 through December 2009. A number of clinical variables were collected through an electronic case report form and analyzed to comprehensively delineate the features of IE. We report the data on patients with definite IE.
Results: A total of 1,082 patients with definite IE were included. Of these, 753 (69.6%) patients had infection on a native valve, 277 (25.6%) on a prosthetic valve, and 52 (4.8%) on an implantable electronic device. Overall, community-acquired (69.2%) was more common than nosocomial (6.2%) or non-nosocomial (24.6%) health care-associated IE. Staphylococcus aureus was the most common pathogen (22.0%). In-hospital mortality was 15.1%. From the multivariate analysis, congestive heart failure (CHF), stroke, prosthetic valve infection, S. aureus, and health care-associated acquisition were independently associated with increased in-hospital mortality, while surgery was associated with decreased mortality.
Conclusions: The current mortality of IE remains high, and is mainly due to its complications, such as CHF and stroke.