New trends in the epidemiological and clinical features of infective endocarditis: results of a multicenter prospective study.

BACKGROUND

The clinical and epidemiological profiles of infective endocarditis (IE) are continuously evolving. We report the results of a 2-year multicenter prospective survey that investigated new trends in the epidemiology, microbiological and clinical features and the prognosis of IE.

METHODS

From January 2000 through December 2001, a prospective multicenter survey on IE was conducted in the region of Piedmont, Italy (4.2 million inhabitants).

RESULTS

A total of 267 patients with suspected IE were enrolled, of whom 147 received a definite diagnosis of IE, as confirmed by pathology or follow-up data. The annual estimated incidence of IE was 36 cases per 1 million inhabitants in urban Turin and 30 cases per 1 million inhabitants in the province of Turin. A predisposing heart disease was detected in 70.8% of cases, with prosthetic valve involvement in 27 (18%). The incidence of injection drug use was 10%. Twenty-two cases (15%) were related to invasive procedures. Causative microorganisms included: streptococci 37.4% (oral streptococci 17.7%, group D streptococci 9.5%, pyogenic streptococci 3.4%, enterococci 6.8%), staphylococci 34%, other pathogens 28.5%. Blood cultures were negative in 25% of cases. The mean time between symptom onset and hospital admission was 39.7 days; this interval was shorter and associated with a poorer prognosis in cases of IE due to Staphylococcus aureus infection (p < 0.001). The delay in carrying out echocardiographic and blood culture evaluation often led to a late diagnosis as defined by the Duke criteria (8.2 +/- 7.4 days after admission). Valve surgery was performed in 31% of patients. The in-hospital mortality was 14% and that at 3 months 18%.

CONCLUSIONS

In Piedmont, the incidence of IE is similar to the rates reported in other recent series. Still, the diagnosis and management of IE remain a challenge. The variegated clinical manifestations of IE and its changing epidemiology require constant surveillance.