Infective endocarditis with symptomatic cerebral complications: contribution of cerebral magnetic resonance imaging.

BACKGROUND: Cerebral complications are well-identified causes of morbidity and mortality in patients with infective endocarditis (IE). Few studies have analysed the impact of brain magnetic resonance imaging (MRI) in IE patients with neurological manifestations.
OBJECTIVES: The aims of this study were to assess the MRI contribution to the management of patients with IE neurological manifestations and to compare cerebral CT and MRI findings.
MATERIAL AND METHODS: Patients with definite or probable IE and neurological manifestations were prospectively enrolled from 2005 to 2008, in a university hospital (Bichat Claude Bernard Hospital, Paris). Clinical and radiological characteristics and echocardiographic findings were systematically recorded. Brain MRI with angiography was performed and compared to available CT scans. The contribution of MRI results to cerebral involvement staging and to therapeutic plans was evaluated.
RESULTS: Thirty patients, 37-89 years old, were included. Nineteen suffered from pre-existing heart disease. Blood cultures were positive in 29 cases and the main micro-organisms were streptococci (n = 14) and staphylococci (n = 13). The IE was mainly located on mitral (n = 15) and aortic valves (n = 13). Neurological events were strokes (n = 12), meningitis (n = 5), seizures (n = 1), impaired consciousness (n = 11) and severe headache (n = 1). MRI findings included ischaemic lesions (n = 25), haemorrhagic lesions (n = 2), subarachnoid haemorrhage (n = 5), brain abscess (n = 6), mycotic aneurysm (n = 7), vascular occlusion (n = 3) and cerebral microbleeds (n = 17). In 19/30 cases, neurological manifestations were observed before the diagnosis of IE. MRI was more sensitive than CT scan in detecting both clinically symptomatic cerebral lesions (100 and 81%, respectively) and additional asymptomatic lesions (50 and 23%, respectively). Therapeutic plans were modified according to MRI results in 27% of patients: antibiotherapy regimen modifications in 7% (switch for molecules with high cerebral diffusion) and surgical plan modifications in 20% (indication of valvular replacement due to the embolic nature of the vegetations revealed by MRI or postponement of surgery due to haemorrhagic lesions). None of the 16/30 (51%) operated-on patients experienced postoperative neurological worsening. In-hospital death occurred in 4 patients.
CONCLUSION: In patients with IE neurological manifestations, MRI revealed a broader involvement of the brain (type and number of lesions) than indicated by clinical signs and/or CT scan. With a better disease staging of neurological manifestations, MRI brain imaging may help in patient management and the decision-making process especially for cardiac surgery indication and timing of valve replacement.