Enterococci, especially Enterococcus faecalis, are among the most common causes of infective endocarditis (IE) and are associated with high mortality rates. Therefore, an accurate diagnosis of IE is an important component of treating patients with enterococcal bacteremia.
In clinical practice, echocardiography is typically the first diagnostic tool used when IE is suspected. However, transthoracic echocardiography has limited sensitivity, whereas transesophageal echocardiography is more invasive and carries procedural risks.
Certain patient-related factors, including structural heart disease or implanted cardiac devices, raise greater concern for IE. The routine use of echocardiography in patients may result in unnecessary testing, increased health care resource utilization, and prolonged hospital admissions.
To address these challenges, clinical prediction scores such as NOVA and DENOVA have been developed to stratify IE risk in patients with enterococcal bacteremia. The adapted NOVA score incorporates 4 weighted clinical components: the number of positive blood cultures, an unknown source of bacteremia, preexisting valvular disease, and the presence of a cardiac murmur.
Zimmermann and colleagues conducted a multicenter retrospective cohort study at 2 tertiary care hospitals in Switzerland, evaluating adults with enterococcal bacteremia who underwent evaluation for IE across multiple clinical cohorts. The study included 827 adult patients with enterococcal bacteremia, who were predominantly older and male.
The authors compared 3 clinical prediction scores to assess their ability to identify patients at low risk for IE and to guide echocardiography use. The primary outcome was the negative likelihood ratio (NLR), with a focus on rule-out performance.
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All 3 prediction scores demonstrated high sensitivity for detecting IE (approximately 89%–99%), though meaningful differences in specificity and imaging burden were observed. Adapted NOVA and DENOVi scores demonstrated the lowest NLRs (both 0.04) with negative predictive values greater than or equal to 99%.
The authors concluded that DENOVi offers a favorable balance between diagnostic safety and resource utilization and may help safely reduce echocardiography in selected patients with enterococcal bacteremia. This study provides an important and contemporary contribution to the literature by validating existing prediction scores for IE in enterococcal bacteremia and introducing a modified, more pragmatic tool (DENOVi) that better reflects clinical practice.
By demonstrating that DENOVi achieves a very low NLR comparable to adapted NOVA while greatly decreasing unnecessary imaging, the study furthers prior work that either overestimated risk (NOVA) or prioritized specificity at the expense of missed cases (DENOVA).
They note that the main limitations of the study include its retrospective design, restriction to 2 Swiss tertiary centers, incomplete imaging in a substantial minority of patients, and the lack of external validation. In practice, DENOVi may be a helpful adjunct to clinical judgment when deciding whether to defer echocardiography in low-risk patients.
It is also noted that this strategy does not appear to meaningfully increase the rate of missed IE. However, widespread adoption would be premature; multicenter validation in diverse health care settings and integration into standardized practice should be performed before DENOVi can be confidently incorporated into routine practice guidelines.
Researchers must continue to investigate the use of clinical trials to improve patient outcomes.