High Disability Rates In Young Patients With PFO Attributable Cryptogenic Ischemic Strokes

Introduction: Approximately 30% of ischemic strokes are cryptogenic and 40-50% of these patients have a patent foramen ovale (PFO) detected during work up. While the risk of ischemic stroke attributed to PFO is 0.5-1% per year, the proportion of disabling ischemic strokes in the setting of PFO is unknown. In this study, we aim to determine differences in rates and predictors of poor outcome in patients with stroke and PFO compared to those without PFO. Methods: This retrospective, observational cohort study included consecutive patients aged 18-60 admitted to our comprehensive stroke center with a diagnosis of ischemic stroke over a two-year period. modified Rankin Score (mRS) was collected at 90-days according to institutional protocol. Poor functional outcome was defined as mRS of 2-6. We compared baseline characteristics of ischemic stroke patients with PFO to those without PFO, and then determined associations with poor outcome using multivariable logistic regression that adjusted for age and stroke severity. We performed similar analyses in the subgroup of patients with cryptogenic stroke. Results: Out of 321 patients with ischemic stroke (mean age 49; 42% women), 146 had cryptogenic stroke - embolic stroke of undetermined source subtype (CS-ESUS). Baseline characteristics, demographics, and stroke severity did not differ between those with PFO when compared to those without PFO both across the entire cohort and in the subgroup of CS-ESUS. Among patients with cs-ESUS with PFO, 48% (10/21) had poor functional outcome, and the rates did not significantly differ based on ROPE score (p = 0.362). In our binary logistic regression model adjusting for age and NIHSS score, the rate of poor functional outcome in patients with CS-ESUS did not significantly differ based on presence vs. absence of PFO (OR 1.10 95% CI 0.39-3.09, p = 0.859). Conclusions: Our study suggests that a significant portion (almost 1 in 2) of cryptogenic strokes in patients with a PFO were disabling at 90 days and disability rates did not significantly differ as a function of PFO attributability of their ischemic stroke. Further studies are needed to identify patients with high-risk PFOs that may especially predispose to disabling strokes and to determine optimal primary stroke prevention strategies.