Abstract TMP41: Local Epidemiology And Diagnostic Results Of Truly Occult Emboli In Patients With ESUS

Abstract

Introduction: Ipsilateral nonstenotic (<50%) internal carotid artery (ICA) plaque, cardiac atriopathy, and patent foramen ovale (PFO) may account for a substantial proportion of embolic stroke of undetermined source (ESUS). Methods: Consecutive stroke patients at our center (2019-2021) with unilateral, anterior ESUS were categorized into the following mutually exclusive etiologies: (1) nonstenotic ipsilateral ICA plaque (≥3mm), (2) atriopathy (sex-adjusted mod-to-severe atrial enlargement) & (3) PFO. Clinical and diagnostic results were compared between patients in each group, and against those with “true ESUS” (who failed to meet criteria for these 3 groups). Results: Of 133 included patients, there was minimal overlap between the mutually exclusive ESUS etiologies (2 having nonstenotic plaque + atriopathy, and 1 having atriopathy + PFO). Older patients more frequently had atriopathy, while patients with PFO had fewer vascular risk factors when compared to the other groups (padj≤0.1; Table). Patients with nonstenotic plaque had more frequent tobacco use (p=0.06), more severe white matter disease (p=0.07), and greater ipsilateral v. contralateral plaque (p<0.01). Twice as many patients with atriopathy presented with an ICA/M1/basilar occlusion (54%) when compared to other groups (p=0.03). Atriopathy was independently associated with older age (ORadj 1.09/year, 95%CI 1.02-1.17) and proximal occlusion (ORadj 16.47, 95%CI 2.86-94.65), with tobacco use associated with a non-atriopathic origin (ORadj 5.56/year, 95%CI 1.07-29.01). Five of 8 patients with atriopathy (63%) monitored with outpatient telemetry had atrial fibrillation, while 3/30 (10%) “true ESUS” and 0/12 (0%) nonstenotic plaque patients had atrial fibrillation. Conclusions: Certain clinical and radiographic features may be useful in predicting the proximal source of occult cerebral emboli, and can be used for cost-effective outpatient diagnostic testing.