Prognostic impact of vegetation size in infective endocarditis

Background and Aims The prognostic impact of vegetation size in infective endocarditis (IE) remains unclear. Our aim was to evaluate the relation between vegetation size and outcome. Methods Our data come from the Spanish IE registry between 2008 and 2024. From 6525 IE patients, 5,000 (76.6%) had vegetations, and 3,592 (55.1%) had documented vegetation size measurements. Patients were categorized into two groups based on maximum vegetation diameter: <10 mm (1,319 - 36.7%) and ≥10 mm (2,273 - 63.3%). Results Compared to patients with small vegetations, patients with vegetations ≥10 mm were younger (68 vs. 70 years, p<0.001), had more frequent right-sided IE (8.0% vs. 4.1%, p<0.001), less prosthetic valve IE (23.9% vs. 29.9%, p<0.001), higher surgical rates (55.9% vs. 40.1%, p<0.001), more embolic events (28.0% vs. 21.4%, p<0.001), higher in-hospital (28.3% vs. 19.6%, p<0.001) and one-year mortalities (35.6% vs. 27.5%, p<0.001). Large vegetation size was an independent predictor of in-hospital mortality (odds ratio [OR] 1.6, 95% confidence interval [CI] 1.3-1.9, p<0.001), embolic events (OR 1.34, 95% CI 1.15–1.55, p<0.001), and one-year mortality (hazard ratio 1.32, 95% CI 1.17–1.50, p<0.001). Vegetation size was an independent predictor of inhospital mortality in left-sided IE (OR 1.7, 95% CI 1.4-2.1, p<0.001) but not in right-sided IE (OR 1.2, 95% CI 0.7-2.3, p = 0.50). Conclusion In patients with IE, large vegetation size is independently associated with embolic events and increased mortality particularly in those with left-sided IE, suggesting the need for more aggressive management in these patients.