Risk Factors of Endocarditis in Patients With Enterococcus faecalis Bacteremia: External Validation of the NOVA Score

The NOVA score is a recently developed diagnostic tool used to identify patients with increased risk of infective endocarditis (IE) among patients with Enterococcus faecalis bacteremia. We aimed to validate the NOVA score and to identify risk factors for IE.

From 1 January 2010 to 31 December 2013, we included 647 consecutive patients with E. faecalis bacteremia. The NOVA score was used in a slightly adapted form; 2/2 positive blood cultures resulted in 5 points, unknown origin of infection in 4 points, prior valve disease in 2 points, and heart murmur in 1 point.

IE was diagnosed in 78 patients (12%). Monomicrobial E. faecalis bacteremia (hazard ratio [HR], 3.60; 95% confidence interval [CI], 1.6-8.0), prosthetic heart valve (HR, 6.2; 95% CI, 3.8-10.1), male sex (HR, 2.0; 95% CI, 1.1-3.8), and community acquisition (HR, 1.8; 95% CI, 1.1-2.9) were independently associated with IE. The adapted NOVA score was applied in the 240 patients examined by echocardiography. A low score (<4) was found in 40 patients (17%), implying a low likelihood of IE. Of the 78 patients with IE, 76 had a high score (≥4), resulting in a sensitivity of 97%, specificity of 23%, a negative predictive value of 95%, and a positive predictive value of 38%.

Monomicrobial E. faecalis bacteremia, community acquisition, prosthetic heart valve, and male sex are associated with increased risk of IE. In our retrospective cohort, the adapted NOVA score performed well, suggesting that it could be useful in guiding clinical decisions.