Possible IE patients had more prosthetic valves and culture-negative IE, while definite IE patients had more complications, surgery, and large vegetations.
What are the differences in clinical characteristics, complications, and outcomes between definite and possible infective endocarditis?
Definite infective endocarditis is associated with higher rates of complications and surgical interventions compared to possible IE, highlighting the need for tailored management strategies.
Abstract Background Infective endocarditis (IE) is a serious disease with high morbidity and mortality. Distinguishing between possible and definite IE can be challenging, and the clinical significance of this distinction remains unclear. A better understanding of these differences, as defined by the Duke diagnostic criteria, may improve patient management and outcomes. Purpose To identify clinical, microbiological, and echocardiographic characteristics according to definite vs. possible IE in a nationwide cohort study. Methods Using the National Danish endocarditis stUdieS (NIDUS) registry (2016–2021), we included all patients with first-time isolated left-sided IE. Patients were classified as definite or possible IE based on the 2015 modified Duke criteria. Data included demographics, comorbidities, echocardiographic findings, microbiological results, complications, and treatments. Results A total of 2,888 patients were included, with 551 (19.1%) classified as possible IE and 2,337 (80.9%) as definite IE. Possible IE patients were older (76.4 vs. 73.6 years, p0.001), with similar sex distribution (65.9% vs. 66.7%, p=0.72). Patients with definite IE more often underwent TEE for diagnosis (93.7% vs. 90.4%), while patients with possible IE more frequently had TTE as their diagnostic echocardiography (9.6% vs. 6.3%) (p = 0.006). PET-CT use was similar (66.4% vs. 67.7%, p = 0.71). Possible IE patients had more prosthetic valves (32.9% vs. 23.9%, p0.001) but fewer vegetations 10 mm (13.8% vs. 33.0%, p0.001). Prosthetic valve endocarditis was more common in possible IE (30.1% vs. 21.5%, p0.001) Native valve endocarditis was more frequent in definite IE (78.6% vs. 69.9%, p0.001). Negative blood cultures were significantly more common in possible IE (30.1% vs. 2.1%; p0.001), while Streptococcusspecies (35.1% vs. 24.3%, p0.001) and Staphylococcus aureus (32.4% vs. 22.3%, p0.001) were more frequent in definite IE. Complications were more common in definite IE, including embolism (16.4% vs. 12.2%, p=0.049), sepsis (12.2% vs. 7.3%, p=0.001), acute kidney injury (18.7% vs. 14.0%, p=0.02), and dialysis (6.0% vs. 3.1%, p=0.006). Surgical treatment was more frequent in definite IE (23.2% vs. 11.1%, p0.001). In-hospital mortality was lower in possible IE (15.6% vs. 18.9%, p=0.07), though not statistically significant. Conclusion In this nationwide cohort, patients with possible IE had more prosthetic valves and culture-negative IE. Patients with definite IE had more complications, surgery, and vegetation 10 mm. In-hospital mortality was similar. These findings emphasize the need for targeted diagnostic and management strategies for patients with possible and definite IE.
Lafta et al. (2025) studied this question. Possible IE patients had more prosthetic valves and culture-negative IE, while definite IE patients had more complications, surgery, and large vegetations.