Acute ischemic brain lesions in infective endocarditis: incidence, related factors, and postoperative outcome.
BACKGROUND
Acute brain infarction affects the timing and regimen of cardiac surgery in patients with infective endocarditis (IE). We aimed to identify preoperative brain MRI characteristics, incidence, and related factors for acute ischemic lesions in left-sided IE patients undergoing cardiac surgery. Furthermore, we investigated whether preoperative acute ischemic lesions are associated with postoperative neurological complications in IE patients.


METHODS
We retrospectively reviewed consecutive patients with a definite left-sided IE who underwent cardiac surgery in 6 university-affiliated hospitals from January 2004 to November 2011. Preoperative brain MRI evaluations were systematically performed on all patients without contraindications, regardless of neurological complications, with the aim of preventing perioperative complications. Patients were included if diffusion-weighted imaging and fluid-attenuated inversion recovery sequences were performed within 14 days after diagnosis. Associations between acute ischemic lesions and related factors were analyzed. Neurological complications within 30 days after surgery were evaluated for postoperative outcome analyses.


RESULTS
Of 139 consecutive patients with left-sided IE who underwent cardiac surgery, 85 patients were evaluated in this study. The mean age was 58 ± 16 years, and 22 patients (26%) were women. Preoperative MRI revealed acute ischemic lesions in 47 patients (55%), and 19 of these patients developed neurological symptoms. Among the patients with ischemic lesions, 24 (60%) had small lesions (<10 mm), 36 (77%) had multiple lesions, and 30 (64%) had lesions in multiple vascular territories. Compared to patients without ischemic lesions, patients with acute ischemic lesions were older and had significantly higher white blood cell counts and plasma C-reactive protein (CRP) levels, but lower hemoglobin levels. Logistic regression analyses showed that the white blood cell count and plasma CRP level were independently associated with acute ischemic lesions [adjusted OR per 1-SD increase were 2.21 (95% CI: 1.23-4.35) and 2.33 (95% CI: 1.27-4.96), respectively]. Three patients developed postoperative neurological complications, but preoperative acute ischemic lesions and postoperative complications were not associated.


CONCLUSIONS
Preoperative MRI detected a high incidence of asymptomatic ischemic lesions in IE patients. Acute ischemic lesions were often small, multiple, and located in multiple vascular territories. Inflammatory reactions may play an important role in the development of ischemic lesions in IE patients.