Risk of embolic events before and after antibiotic treatment initiation among patients with left-side infective endocarditis

Purpose Embolic events (EEs) are a common complication of left-side infective endocarditis (IE). The aim of the present study was to identify risk factors for the occurrence of EEs before or after antibiotic treatment instauration among patients with definite or possible IE. Methods This retro-prospective study was conducted at the Lausanne University Hospital, Lausanne, Switzerland, from January 2014 to June 2022. EEs and IE were defined according to modified Duke criteria. Results A total of 441 left-side IE episodes were included (334: 76% were definite and 107; 24% possible IE). EE were diagnosed in 260 (59%) episodes; in 190 (43%) before antibiotic treatment initiation and 148 (34%) after. Central nervous system (184; 42%) was the most common site of EE. Multivariable analysis identified S. aureus ( P 0.022), immunological phenomena ( P < 0.001), sepsis ( P 0.027), vegetation size ≥ 10 mm ( P 0.003) and intracardiac abscess ( P 0.022) as predictors of EEs before antibiotic treatment initiation. For EEs after antibiotic treatment initiation, multivariable analysis revealed vegetation size ≥ 10 mm ( P < 0.001), intracardiac abscess ( P 0.035) and prior EE ( P 0.042), as independent predictors of EEs, while valve surgery ( P < 0.001) was associated with lower risk for EEs. Conclusions We reported a high percentage of EEs among patients with left-side IE; vegetation size, intracardiac abscess, S. aureus and sepsis were independently associated with the occurrence of EEs. In addition to antibiotic treatment, early surgery led to further decrease in EEs incidence.