Negative blood culture infective endocarditis in the elderly: long-term follow-up.

Background And Aim: Since the appearance of transesophageal echocardiography, the long-term prognosis of patients with negative blood culture infective endocarditis (NBCIE) has been found to be similar to that of patients with positive blood culture infective endocarditis (PBCIE). Nevertheless, the prognostic implications of NBCIE in the elderly (>65 years) has not, to date, been well documented. Our aim was to study the long-term prognosis of elderly patients with NBCIE and compare it with that of elderly patients with PBCIE.

Methods: Our study group was composed of 60 consecutive patients >65 years old with a diagnosis of IE (confirmed by vegetation analysis or following Duke's criteria). Every patient underwent transthoracic and transesophageal echocardiography. Fifty patients (83.3%) had PBCIE and 10 (16.7%) had NBCIE. All patients were followed up long-term, and the study end point was a composite one of death or need for valvular heart surgery.

Results: Mean age was 72.9 +/- 5 years (56.7% male). Similar clinical and echocardiographic characteristics were found in both groups. Global mortality, need for surgery, predisposing factors and infection location were also similar in both groups. In addition, no differences were found in the long-term prognosis (log rank p = 0.29).

Conclusions: In our series, the long-term prognosis in elderly patients with IE is independent of the presence of a negative or positive blood culture. Thus, age cannot be considered an independent risk factor of negative outcome in elderly patients with NBCIE.