Transcranial Doppler Studies for Managing Ischemic Stroke in Infective Endocarditis

Introduction Infective endocarditis (IE) has a high risk of neurovascular complications, including ischemic and hemorrhagic stroke from septic emboli, and mycotic aneurysms. Treatment of this condition requires antibiotics and often valve replacement surgery, however the optimal timing for surgery is complicated by concomitant strokes and risk of hemorrhagic conversion with heparinization during the procedure. Transcranial doppler (TCD) studies assessing for high intensity transient signals (HITS) can detect ongoing microemboli. Here we present an illustrative case report with a patient with infective endocarditis and stroke with positive TCD HITS studies. Case report A male patient in his third decade of life with history of intravenous drug use presented with acute ischemic right MCA stroke (Figure 1A), not a candidate for acute intervention, and fever. His etiology was concerning for septic emboli in the setting of intravenous drug use. CTA showed a right distal M2/M3 occlusion; no mycotic aneurysms were identified. He was found to have polymicrobial bacteremia with MRSA and Enterococcus faecalis complicated by mitral valve endocarditis. With infectious disease consulted, he was started on antibiotics, daptomycin 10mg/kg and ceftaroline 600mg. He had a transthoracic echo with a 1.5 x 0.75 cm2 mitral valve vegetation, deemed not a surgical candidate. He had a TCD HITS study on hospital day 6 which showed a positive HITS in his right MCA (Figure 1B). The following day, a stroke code was activated for unresponsiveness, CT head with hemorrhagic right MCA stroke with IVH and midline shift (Figure 1C) with loss of brainstem reflexes. Unlikely to benefit from a neurosurgical intervention and despite optimum medical management, the patient progressed to brain death on hospital day 13 in the setting of cerebral herniation. Conclusion TCD HITS studies are non‐invasive imaging tests that detect ongoing septic emboli in patients with infective endocarditis. TCD HITS has the potential to identify high risk infective endocarditis patients and to change management in these patients through antibiotics recommendation and can assist with guiding surgical timing, hopefully to improve outcomes. More research is necessary to evaluate the potential of TCD HITS.