Cerebral microbleeds predict impending intracranial hemorrhage in infective endocarditis.

BACKGROUND

Cerebral microbleeds (CMBs) detected by T2*-weighted MRI are a potential indicator of hypertension, microvascular disease and hemorrhagic stroke. An association between infective endocarditis (IE) and CMBs has been reported recently, but the clinical significance remains unclear. We hypothesized that CMBs in patients with IE are associated with vascular vulnerabilities such as mycotic aneurysm or pyogenic vasculitis.

METHODS

We retrospectively reviewed 26 consecutive patients with definite IE who underwent T2*-weighted MRI and were admitted to 2 medical centers in Osaka, Japan, between January 2006 and June 2010. We examined the incidence of symptomatic intracranial hemorrhage (ICH) occurring after initial MRI examination and investigated the association between ICH, CMBs and other clinical characteristics.

RESULTS

CMBs were identified in 14 patients (54%), and 72% of CMBs were found in the lobar region. Symptomatic ICH was observed in 8 patients (31%) during the 3-month follow-up period after initial MRI examination. In multiple logistic regression analyses, the presence of preceding ICH [odds ratio (OR) 40.0, 95% confidence interval (CI) 2.5-2,870] and the presence of CMBs (OR 34.0, 95% CI 1.3-17,300) were independent predictors of the development of ICH. Using cutoff values for CMBs of ≥2 and ≥3, the adjusted ORs for ICH increased (OR 42.1, 95% CI 1.9-24,300, and OR 70.1, 95% CI 2.5-105,000, respectively).

CONCLUSIONS

In addition to prior ICH, the presence of CMBs was a strong predictor of impending ICH in patients with IE. CMBs might represent vascular vulnerability related to IE.