Abstract Body: Introduction: Mechanical circulatory support (MCS) carries a high risk of neurologic complications, with estimates of arterial ischemic stroke (AIS) to be between 5 and 30%. We report our cohort of children on Ventricular Assist Device (VAD) or Extracorporeal Membrane Oxygenation (ECMO) support who suffered AIS, and describe stroke treatment and outcomes in this high-risk population.

Methods: The Stanford Pediatric Stroke Registry retrospectively and prospectively enrolled children aged 30 days-22years admitted to our quaternary care pediatric hospital between 2007-2024 with confirmed AIS on neuroimaging. Demographic, clinical, radiographic, treatment and outcome data were collected via chart review and entered into a secure, HIPAA-compliant RedCAP database. Children on MCS at the time of stroke were compared with non-MCS patients and analyzed using descriptive statistics.

Results: A total of 35/207 (16.9%) patients were identified as having an AIS while on MCS; demographics and clinical characteristics are shown in Table 1. Overall, MCS patients were younger and were more likely to have congenital or acquired heart disease than non-MCS patients. Stroke presentation, treatment and outcomes are shown in Table 2. Stroke symptoms were detected upon weaning sedation in the majority of MCS patients (37.1%), and clinical exam was confounded by paralysis or sedation in 82.9%. Over half of MCS patients had peri-procedural strokes, and stroke was detected within 24 hours in 45.8%. Large Vessel Occlusion (LVO) was detected in over half of MCS patients; however, less than a third underwent vessel imaging as part of their initial stroke neuroimaging. Intravenous thrombolysis was contraindicated in all MCS patients. Thrombectomy was performed on 2 MCS patients after ECMO decannulation and was not pursued for most MCS-LVO patients primarily due to large core or completed stroke (Figure 1). Mortality and morbidity were high in the MCS cohort, with 45.5% of MCS patients having an mRS of 5-6 on discharge, compared to 14.4% of non-MCS patients.

Conclusions: Pediatric AIS on MCS carries a high risk of morbidity and mortality and can be challenging to recognize acutely, with the post-procedural period being particularly high-risk. Advanced neuroimaging and neuromonitoring may play an important role in earlier detection of stroke and eligibility for thrombectomy in this population.