[Infectious endocarditis: morbi-mortality in Chile. Results of the National Cooperative Study of Infective Endocarditis (1998-2002)].

BACKGROUND

Infective endocarditis is a severe condition, with a mortality that fluctuates between 16 and 25% in the Metropolitan area of Chile.

AIM

To perform a prospective assessment of clinical and microbiological features of patients with infective endocarditis in Chile.

MATERIAL AND METHODS

Collaborative study of regional hospitals in the whole country and teaching hospitals in Santiago. Patients with a possible or definitive infective endocarditis, according to Duke's criteria, were included in the protocol and a structured data entry form was completed.

RESULTS

Three hundred twenty one patients (65% male, mean age 49 +/- 16.5 years) were studied. According Duke's criteria, 89% had a definitive and 11% a possible endocarditis. The subacute form occurred in 64% of patients. The most frequent predisposing cardiopathies were rheumatic in 25%, prosthetic valves in 15% and congenital in 13%. There was no evidence of cardiopathy in 20%. Twenty percent of patients were on hemodialysis, 11% were diabetic and only one patient abused intravenous drugs. The most frequent complication was cardiac failure in 59% of cases, followed by renal failure in 32% and embolism in 28%. The most frequent causing organism was coagulase positive Staphylococcus in 35%. Blood cultures were negative in 28% of cases from the metropolitan region, in 56% of cases from the north and 38% of cases from the south. Echocardiographic diagnosis was done in 92% of cases. Aortic valve was involved in 42% and mitral valve in 29%. Successful antimicrobial treatment was achieved in 59% of patients. Thirty five percent of patients were subjected to surgical procedures with a 78% survival. Overall mortality was 29%. Univariate analysis identified sepsis, an age over 60 years and the presence of cardiac or renal failure as prognostic indicators of mortality. On multivariate analysis, the identified prognostic indicators were the presence of sepsis, renal failure, mitroaortic involvement associated to combined surgery and failure of antimicrobial treatment not associated to surgery.

CONCLUSIONS

Subacute form is the most common presentation of infective endocarditis and rheumatic valve disease is the most common underlying cardiac lesion. Intravenous drugs users infective endocarditis is exceptional in Chile. The most frequent causing agent is coagulase positive Staphylococcus and the most frequent complication is cardiac failure. Surgical and overall mortality were 22 and 29% respectively. Sepsis, renal failure, combined surgical procedures, failure of medical treatment were identified as prognostic indicators of mortality.