Epidemiological features of infective endocarditis (IE) have changed during the last decades because of an increase in degenerative valvular disease in the elderly, placement of prosthetic valves, and exposure to invasive procedures. Although lower mortality rates have been observed, overall mortality remains high.

The aim of this study was to analyse epidemiology, and predictors of 6-month mortality in IE.

This was a prospective study that enrolled 240patients admitted for IE in the cardiology department of Monastir hospital between 1983 and 2017. Included Patients had definite IE according to the modified Ducke criteria.

Thirty-two percent of episodes involved prosthetic valves. Thirty percent of episodes were nosocomial. Thirty-three percent included staphylococci, 22% streptococci, and 10% enterococci. At least one complication occurred in 59% of the episodes and 43% had surgical intervention. Six-month mortality was 20%: 29% for staphylococci, 19% for enterococci, and 9% for streptococci. Seventy-one percent of patients with a contraindication to surgery died when compared with 7% with medical treatment without a contraindication and 13% with surgical treatment. In multivariable logistic regression, predictors of 6-month mortality were age (P=0.04), the causative microorganism (P=0.03), and treatment group (P=0.03).

Compared with older series, we observed more prosthetic valve IE, nosocomial IE, and surgery. Staphylococcus aureus was the predominant microorganism. Age, staphylococci, and the contraindication to surgery were the main predictors of 6-month mortality.