Stroke Recurrence in Patients with Patent Foramen Ovale after Cerebral Ischemia
Paradoxical embolism through a patent foramen ovale (PFO) is a potential cause for ischemic stroke, particularly in younger patients. Longterm data concerning stroke recurrence in patients with PFO is scarce. We performed a longterm follow-up in patients with PFO, diagnosed in association with cerebral ischemia in our department from 1991 to 1997. We performed telephone interviews with a standardized questionnaire and neurologic examinations. PFO-size was assessed semiquantitatively as described before (<10; 10–99; >99). Univariate and multivariate tests were performed for all potential risk factors of stroke recurrence in patients with PFO. We examined 281 patients with a mean age of 48 years and a mean follow-up interval of 39 months. Recurrent cerebral ischemia occured in 59 patients. Recurrence rate was 6.9% per year. In patients on warfarin, recurrence rate was significantly lower than in patients on aspirin or without therapy (4.2% per year, p= 0.001). In patients without therapy, stroke recurrence rate was significantly higher than in patients on warfarin or aspirin (13% per year, p= 0.002). Recurrence was not associated with PFO-size and spontaneous shunt. Ventricular septum aneurysm (VSA) was not more frequent in patients with recurrent stroke. Recurrence rate was significantly higher in patients with concurrent etiologies (p= 0.001). Stroke recurrence rate in patients with PFO after cerebral ischemia is higher in this large series than in some smaller previous series. Warfarin significantly lowers stroke recurrence rate. Surprisingly, recurrence rate was not associated with PFO-size, spontaneous shunt or VSA. Thererfore, no subgroups could be identified, which are at higher risk. Anticoagulation seems the treatment of choice for secondary prevention, independent from PFO-size or spontaneous shunt.