Background and purpose: Cerebral lesions are frequent complications of infective endocarditis (IE) and have a prognostic impact. Cerebral MRI identifies lesions in a high number of patients. However, their determinants have not been identified. The aim of the study was to define the determinants of cerebral lesions in patients with IE undergoing systematic cerebral MRI.
Methods: Determinants of ischemic lesions and of microbleeds were prospectively analyzed in 120 patients with left-sided IE, using systematic cerebral MRI.
Results: Median age was 60 years (interquartile range 51-72); IE occurred on a prosthetic valve in 37 patients (30.8%) and was due to Streptococci in 47 patients and Staphylococci in 36; 15 (12.5%) had neurological symptoms. MRI detected ischemic lesions in 64 patients (53.3%; territorial lesions in 32 and small lesions in 57) and microbleeds in 72 (60.0%). In multivariate analysis, ischemic lesions were associated with vegetation length (odds ratio 1.10/mm; 95% confidence interval 1.03-1.16; P=0.003) and Staphylococcus aureus IE (odds ratio 2.65; 95% confidence interval 1.01-6.96; P=0.05). A vegetation length >4 mm identified ischemic lesions with a sensitivity of 74.6% and a specificity of 51.5%. Microbleeds were associated with prosthetic IE (odds ratio 8.01; 95% confidence interval 2.58-24.90; P=0.0003) and not with prior anticoagulant therapy (P=0.67).
Conclusions: Systematic cerebral MRI frequently detects ischemic lesions and microbleeds during acute IE. The high sensitivity of MRI shows that each millimeter increase in vegetation length is associated with a 10% increase in the rate of ischemic lesions. Conversely, microbleeds are associated only with prosthetic IE in this study.
Clinical trial registration url: http://www.clinicaltrials.gov. Unique identifier: NCT00144885.
Keywords: echocardiography; endocarditis; microbleeds; stroke.