Abstract TP240: Non-Stenotic Cervical Carotid Plaque is More Common in Patients With ESUS

Background: One in 5 strokes have an embolic appearance but with no clear source (ESUS). Recent data have suggested anticoagulation is no better than antiplatelet therapy in preventing stroke recurrence in these patients, arguing against a cardioembolic mechanism. It is possible that non-stenotic cervical arterial plaque may be a mechanism of stroke in some patients with ESUS. Methods: A retrospective cohort of consecutive adults admitted with stroke to 3 hospitals was queried (08/2015 - 05/2017). Patients with acute, unilateral, anterior circulation infarcts who underwent CT angiography of the neck within 10 days of admission and were diagnosed with ESUS or a cardiac source of embolism (CE) were included, as determined by the modified TOAST criteria. The pre-specified primary outcome was moderate plaque (≥3mm), as defined in a recently published cohort of ESUS patients, and was compared between ipsi- and contra-lateral ICAs. Plaque features and degree of stenosis were secondary outcomes. Results: Of 786 screened patients, 97 patients with ESUS (12%) and 115 patients with CE (14%) were included. The median age was 71y (IQR 60-81) and 117 were female (54%). Moderate plaque was more frequently ipsilateral than contralateral to the infarct in patients with ESUS (42% vs. 30%, p McNemar =0.03) but not in CE (37% vs. 33%, p=0.53). There was no meaningful ICA stenosis for either side in the cohort (median stenosis 0% [IQR 0-10%]), nor was there a difference when sides were compared among patients with ESUS (median 0 vs. 0%, p=0.85) or patients with CE (0 vs. 0%, p=0.343). Conclusion: In this cohort, there was more moderate cervical ICA plaque ipsilateral to infarcts in patients with ESUS, but not in patients with CE, suggesting an underlying atherothromboembolic mechanism for some. As such, among ESUS patients, those with ipsilateral, non-stenotic ICA plaque may not benefit from anticoagulation compared to antiplatelet therapy to prevent recurrent stroke.