Abstract TP202: Nonstenotic Carotid Plaque As An Inverse Predictor Of PFO In Cryptogenic Stroke

Background: Embolic stroke of undetermined source (ESUS) accounts for up to 20% of all strokes. Potential contributors to ESUS include patent foramen ovale (PFO) and non-stenotic plaque (<50%, NSP) of the ipsilateral internal carotid artery (ICA). To better differentiate these as unique mechanisms, we explored the prevalence of each in a multicenter observational cohort. Methods: A retrospective multicenter cohort of consecutive patients with ESUS was queried (2015-2021). Patients with unilateral, anterior circulation ESUS who had a CTA neck scan and a transthoracic echocardiogram (TTE) and/or transesophageal echocardiogram (TEE) with adequate visualization of a PFO were included. Patients with prior carotid stent, endarterectomy or alternative etiologies were excluded from the study. Descriptive statistics were used to characterize patients with and without PFO, with multivariable logistic regression used to predict the presence of a PFO based on clinicoradiographic factors as well as degree of luminal stenosis and ipsilateral plaque thickness >3mm, based on previously published thresholds of clinical relevance. Results: Of the 234 included patients with unilateral anterior ESUS and adequate TTE or TEE, 17 (7.3%) had a PFO and 64 (27.4%) had ≥3mm of ipsilateral ICA plaque. Patients with PFO had significantly less NSP and less ipsilateral cervical ICA stenosis (0% [IQR 0-0%] vs. 0% [IQR 0-50%], p=0.03; Table). After adjustment for all predictors of PFO in multivariable regression (p<0.2: non-White race, Hispanic ethnicity, and ipsilateral plaque thickness), ipsilateral NSP was non-significantly associated with an 86% lower odds of finding a PFO (ORadj per 1cm of plaque 1.86, 95%CI 0.97-3.55, p=0.06). No patients with a PFO had ≥3mm of ipsilateral ICA plaque. Conclusion: Ipsilateral NSP is more common in ESUS patients without a PFO. While this study is limited by the small PFO event rate, it supports the notion that NSP and PFO may be independent contributors to ESUS.