Neurologic Complications of Infective Endocarditis: Risk Factors, Outcome, and Impact of Cardiac Surgery: A Multicenter Observational Study

Study Questions:

Among patients with left-sided infective endocarditis (IE), what is the incidence of neurologic complications, the risk factors for their development, their influence on clinical outcome, and the impact of cardiac surgery?


Prospectively collected data from a multicenter cohort of 1,345 consecutive episodes of left-sided IE from eight centers in Spain were retrospectively analyzed. Cox regression models were developed to analyze variables predictive of neurologic complications and associated mortality.


A total of 340 patients (25%) experienced neurologic complications: 192 patients (14%) had an ischemic event, 86 (6%) encephalopathy/meningitis, 60 (5%) hemorrhage, and two brain abscess. Independent risk factors associated with all neurologic complications were: vegetation size ≥3 cm (hazard ratio [HR], 1.91), Staphylococcus aureus etiology (HR, 2.47), mitral valve involvement (HR, 1.29), and anticoagulant therapy (HR, 1.31). Anticoagulant therapy was particularly related to a greater incidence of hemorrhagic events (HR, 2.71). Overall mortality was 30%, and neurologic complications had a negative impact on outcomes (45% of deaths vs. 24% in patients without neurologic complications, p < 0.01), although only moderate to severe ischemic stroke (HR, 1.63) and brain hemorrhage (HR, 1.73) were significantly associated with a poorer prognosis. Antimicrobial treatment reduced (by 33% to 75%) the risk of neurologic complications. In patients with hemorrhage, mortality was higher when surgery was performed within 4 weeks of the hemorrhagic event (75% vs. 40% with later surgery).


Moderate to severe ischemic stroke and brain hemorrhage were found to have a significant negative impact on the outcome of IE. The authors concluded that early, appropriate antimicrobial treatment is critical, and transitory discontinuation of anticoagulant therapy should be considered.


Left-sided IE is a serious condition associated with substantial mortality and morbidity even with appropriate treatment. Data from this large patient cohort reinforce the substantial risk of neurologic complications associated with IE.

Keywords: Prognosis, Spain, Risk Factors, Meningitis, Staphylococcus aureus, Brain Abscess, Endocarditis, Bacterial

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