Title: Effect of Early Cerebral Magnetic Resonance Imaging on Clinical Decisions in Infective Endocarditis: A Prospective Study
Topic: Noninvasive Cardiology
Date Posted: 5/14/2010
Author(s): Duval X, Iung B, Klein I, et al., on behalf of the IMAGE (Resonance Magnetic Imaging at the Acute Phase of Endocarditis) Study Group.
Citation: Ann Intern Med 2010;152:497-504.
Clinical Trial: No
Study Question: Does early cerebral magnetic resonance imaging (MRI) affect the diagnosis and management of infective endocarditis in hospitalized adults?
Methods: In a single-center (tertiary care hospital in France) prospective study performed between June 2005 and October 2008, cerebral MRI with angiography was performed in 130 patients hospitalized with infective endocarditis up to 7 days after admission and before any surgical intervention. Two experts jointly established the endocarditis diagnostic classification (modified Duke criteria), and therapeutic plans just before and after MRI.
Results: Endocarditis was initially classified as definite in 77 patients, possible in 50, and was excluded in 3. Acute neurologic symptoms were present in 16 patients (12%). Cerebral lesions were detected on MRI in 106 patients (82% [95% confidence interval, 75-89%]), including ischemic lesions in 68, micro-hemorrhages in 74, and silent aneurysms in 10. Solely on the basis of MRI results and excluding micro-hemorrhages, diagnostic classification of 17 of 53 (32%) cases of nondefinite endocarditis was changed to either definite (14 patients) or possible (3 patients). MRI results led to modification of endocarditis therapeutic plan in 24 (18%) of 130 patients, including surgical plan modifications for 18 (14%). Overall, early MRI led to modifications of diagnosis or therapeutic plan in 36 patients (28% [confidence interval, 20-36%]). (Investigators did not assess whether MRI-related changes in diagnosis and therapeutic plans improved patient outcomes, or led to additional and potentially unnecessary procedures, and/or increased costs.)
Conclusions: Cerebral lesions were identified on MRI in many patients with endocarditis, but no neurologic symptoms. The MRI findings affected both diagnostic classifications and clinical management plans.
Perspective: Other recently published data similarly found very high rates of both subclinical brain embolus (~48%) and any acute brain embolus (~80%) among patients with left-sided infective endocarditis (Circulation 2009;120:585-91). The present study used these data to show an increase in the rate of diagnosis of infective endocarditis, and altered medical and/or surgical management in patients with evidence of subclinical brain pathology (ischemic lesions, aneurysms). However, as the authors note, it is not known whether the additional data actually should have altered therapy, or in any way improved outcomes. If existing diagnostic criteria and therapeutic recommendations include the presence or absence of clinically apparent embolic events, it does not logically follow that management necessarily should be altered by extrapolation to include subclinical events. It is clear that doing more tests will result in the detection of more abnormalities. However, improved clinical outcomes should remain the relevant endpoint. David S. Bach, M.D., F.A.C.C.
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