Cerebral Microembolization in Left Ventricular Assist Device Associated Ischemic Events

Introduction: The significance of microembolic signals (MES) detected by transcranial Doppler ultrasound emboli monitoring (TCD-e) in patients supported with left ventricular assist devices (LVAD) remains unclear. We aimed to investigate the relationship between cerebral microembolization detected by TCD-e and acute ischemic events in LVAD patients. Methods: We reviewed consecutive patients with acute ischemic stroke or transient ischemic attack (TIA) in a prospectively collected database of LVAD patients. TCD-e exams consisted of monitoring the middle cerebral arteries for microembolic signals (MES) over 30 minutes. Results: Of 515 persons with LVAD, 41 TCD-e studies were performed in 35 patients with acute ischemic stroke or transient ischemic attack (TIA) in a median of 1 day (Interquartile range [IQR]: 0-2) after the event. MES were present in 15 (44%) TCD-e studies with a median MES count of 4 (IQR: 2-15.5). Bloodstream infections were more common in patients with MES (38% versus 8%, P =.039). There were trends for lower international normalized ratio (1.39 versus 1.69, P =.214), lower activated partial thromboplastin (33.2 versus 36.6, P =.577), higher lactate dehydrogenase (531 versus 409, P =.323) and a higher frequency of pump thrombosis (13% versus 8%, P =.637) in patients with MES compared with those without MES. Conclusions: LVAD patients with acute ischemic stroke or TIA have a high prevalence of MES on TCD-e, which may serve as a marker for a prothrombotic state. Further study of MES in LVAD patients is warranted.