Embolic Burden and Echocardiographic Predictors in a Real-World Cohort of Infective Endocarditis: A 15-Year Single-Center Retrospective Study

Background/Objectives: Systemic embolization is a common and serious complication of infective endocarditis (IE). This study evaluated the association between vegetation morphology and embolic events and assessed whether echocardiographic parameters provide incremental discriminatory value beyond clinical variables. Methods: We conducted a retrospective cohort study including 164 consecutive adults hospitalized with definite IE between 2011 and 2025 at a regional referral center. Vegetation presence, size, and mobility were assessed using transthoracic (TTE) and transesophageal echocardiography (TEE), according to clinical indication. The primary endpoint was overall in-hospital embolic burden, including embolic events present at admission, occurring during hospitalization, or incidentally detected during diagnostic work-up. Associations were analyzed using univariate and multivariable logistic regression, and model discrimination was evaluated using receiver operating characteristic (ROC) analysis. Results: Embolic events occurred in 96 patients (58.5%). Vegetations were identified in 68.3% of patients and were more frequent among those with embolization (78.1% vs. 54.4%). Mobile vegetations were more common in patients with embolic events (77.1% vs. 27.9%, p < 0.001), as were vegetations > 10 mm (61.5% vs. 38.2%, p = 0.006). Compared with non-mobile vegetations ≤ 10 mm, mobile vegetations ≤ 10 mm were associated with higher odds of embolization (OR 5.4), and mobile vegetations > 10 mm showed a similar association (OR 7.14). In multivariable analysis, vegetation mobility remained independently associated with embolic events. The clinical model demonstrated moderate discrimination (area under the curve [AUC] 0.71), which improved with the addition of vegetation mobility (AUC 0.81; p = 0.005) and size > 10 mm (AUC 0.79; p = 0.016), with no significant difference between the enhanced models. Conclusions: Both vegetation mobility and size > 10 mm were associated with overall in-hospital embolic burden and may provide complementary information for embolic risk stratification. These findings should be considered exploratory and require confirmation in prospective studies with standardized imaging and validation procedures.