The Truth Perturbs in the Seemingly Negligible; Brain Magnetic Resonance Imaging and Endocarditis Ari A. Mennander, MD, PhD Here is the puzzle in a nut-shell: a patient with endocarditis is referred for surgery. If there is no hemorrhagic cerebral insult, prompt surgery is advised. If there are no neurologic symptoms, should the patient undergo a preoperative magnetic resonance imaging of the brain (MRI)? MRI reveals coincidental cerebral variants such as micro- bleeds. 1 The clinical significance of these enigmatic lesions is uncertain during endocarditis; are they only harbingers of old age in some patients? 1 What are these lesions, if they are not associated with endocarditis or cerebral hemorrhage? Is surgery for endocarditis detrimental to some of the patients with cerebral microbleeds? Which patients, if any, should be directed for conservative treatment? In the current article by Murai et al, 2 patient groups with endocarditis were compared in terms of positive vs negative cerebral microbleed lesions. 2 The authors tackled open- mindedly the challenging significance of these incidental lesions during endocarditis. The article set clear definitions for the lesions according to MRI; cerebral microbleeds were defined with a T2-star-weighted imaging or susceptibility- weighted imaging: a hypointense lesion less than 10 mm in diameter was found in 40 out of 74 patients (54%). The rest of the patients had neither cerebral microbleeds nor bigger cerebral hemorrhage. A clear surgical strategy was applied and encompassed surgery for heart failure refractory to medi- cal therapy, persistent infection, repeat embolization, high embolic risk, and presence of perivalvular extension of endo- carditis. Early surgery was defined as surgical intervention within 14 days after the initial diagnosis. Late surgery was indicated whether severe regurgitation after conventional treatment and the resolution of infection occurred. According to multivariate Cox regression analysis adjusted for age and operative risk, the presence of cerebral microbleeds did not impact clinical outcome and all-cause death in patients with endocarditis. It is tempting to speculate that clinical assessment suffices to detect whether the patients are neurolog- ically suitable for surgery, since only hemorrhage of a consider- able size determines the fate of the patient; microbleeds are indicative of patient age, and age alone does often not matter in decision-making for surgery. Are these conclusions too presumptive and optimistic? Indeed, the critical reader mirrors the results of this study to everyday clinical judgment, and the authors of the study remind that precautious interpretation is mandatory. The patient groups were not comparable, and the patients with cerebral microbleeds were substantially older. There was a significantly higher percentage of staphylococcal endocarditis in the patients with cerebral microbleeds as compared with those without the lesions. Even if the patients had not preoper- ative neurologic symptoms, they may have had preoperative Ari A. Mennander, MD, PhD. Central Message Do incidental cerebral microbleeds found at magnetic resonance imaging impact clinical decision-making in patients with endocarditis? Tampere University Heart Hospital and Tampere University, Tampere, Finland Disclosures: Author has nothing to disclose with regard to commercial support. Address reprint requests to Ari A. Mennander, MD, PhD, Tampere Uni- versity Heart Hospital, Ensitie 4, SDSKIR, PL 2000, Tampere Finland. E-mails: ari.mennander@sydansairaala.fi, ari.mennander@hotmail.com DOI of original article: http://dx.doi.org/10.1053/j.semtcvs.2018.09.020. 1 1043-0679/$see front matter © 2018 Elsevier Inc. All rights reserved. https://doi.org/10.1053/j.semtcvs.2018.11.011 ADULT  Editorial Commentary