Factors related to recurrence of paradoxical cerebral embolism due to patent foramen ovale

Patent foramen ovale (PFO) is an important etiology of ischemic stroke in young adults. We investigated factors contributing to recurrent ischemic stroke in patients with PFO. Subjects comprised 47 patients (mean age, 56.8 ± 14.2 years; range 23–74 years) with ischemic stroke due to PFO who were admitted to our hospital between April 2007 and February 2011. Mean duration of follow-up was 34.5 ± 13 months. Recurrence occurred in 11 cases. Annual recurrence rate was 23.4%. We investigated relationships between recurrence of ischemic stroke and size of PFO (large, >4 mm; medium, 2–3.9 mm; small, <1.9 mm; absent group), maximal number of microbubbles (determined as the number of microembolic signals: small, 0–5; moderate, 6–25; and multiple, ≥26), massive bubble on contrast transesophageal echocardiography or atrial septal aneurysm, D-dimer level and antithrombotic therapy. Univariate analysis showed size of the PFO (P = 0.013), number of microbubbles (P = 0.021), and presence of a massive bubble on echocardiography (P = 0.04) were related to recurrence of ischemic stroke. Logistic analysis identified size of the PFO (P < 0.05) and massive bubble on echocardiography (P < 0.05) as factors related to recurrence of ischemic stroke. In conclusion, size of the PFO and presence of a massive bubble were considered to be factors associated with recurrence of ischemic stroke due to PFO.