Patent Foramen Ovale and Risk of Recurrence in Stroke of Determined Etiology

Objective: Patent foramen ovale (PFO) is often found in stroke patients with determined etiologies. PFO may be the actual cause of stroke in some of them. We determined whether the risk of recurrent ischemic stroke differs with PFO status in stroke patients with determined etiologies. Methods: This study included consecutive patients with stroke of determined etiology who underwent transesophageal echocardiography. We compared the rates of recurrent cerebral infarction in patients with versus without PFO, and according to PFO-Associated Stroke Causal Likelihood (PASCAL) classification. Results: Of 2,314 included patients, 827 (35.7%) had PFO. During a median follow-up of 4.4 years, cerebral infarction recurred in 202 (8.7%). In multivariate modified Cox regression analyses, recurrence of infarction did not significantly differ between patients with PFO and those without PFO (hazard ratio [HR] = 0.86, 95% confidence interval [CI] = 0.64–1.17, p = 0.339). Interaction analysis showed a significant effect of PFO in patients aged <65 years (adjusted p for interaction = 0.090). PFO was independently associated with a decreased risk of recurrent infarction in patients younger than 65 years (HR = 0.41, 95% CI = 0.20–0.85, adjusted p = 0.016). Patients with probable PFO-associated stroke on the PASCAL classification had a significantly lower risk of recurrent infarction than those without PFO (HR = 0.31, 95% CI = 0.10–0.97, p = 0.044). Interpretation: Considering the generally low risk of recurrence in PFO-associated stroke, PFO may be the actual cause of stroke in some patients with determined etiologies, especially younger patients or those with PFO features of probable PFO-associated stroke. ANN NEUROL 2022;92:596–606.