AFLOAT is a national, multicenter, randomized, controlled, open-label superiority study with a blind evaluation of all the endpoints (PROBE design).~The interventional phase is followed by an observational phase as long as the patient is implanted with the ICM during when only the data of the device will be collected.~Screening and selection occurs before the procedure of PFO closure and an inform consent form is signed.~During the procedure of PFO closure, a small ICM (CONFIRM RX, ABBOTT) providing a long-term monitoring is implanted to detect all AF or atrial flutter episodes.~Immediately after PFO closure, patients are randomly assigned, in a 1:1:1 ratio, in 3 groups : flecainide (150 mg per day in a single sustained-release dose) for 6 months (in addition to standard of care), flecainide (150 mg per day in a single sustained-release dose) for 3 months (in addition to standard Clinical follow-up is conducted during hospitalization, at 3 months (M3) and 6 months (M6-end-of-interventionnal phase) after discharge. A contrast echocardiography is recommended between 1 and 6 months. Telemonitoring provides notifications in case of arrhythmic event.~An observational period in patients who will keep the ICM beyond the 6-month follow-up period. Atrial fibrillation detection will be continued.
About 30% of ischemic strokes are cryptogenic. Patent Foramen Ovale (PFO) is present in about 25% of the general population. In cryptogenic strokes, PFO has been shown to be overrepresented and recent intervention studies have confirmed that PFO has a causal link with stroke. In patients with recent cryptogenic stroke, these randomized studies have shown at least 50%-reduction of recurrent neurological events after PFO percutaneous closure compared with medical therapy alone. At the The risk of AF reported in these studies in certainly largely underestimated as only symptomatic and recorded episodes of AF have been declared. Patients often report palpitations without a dia gnosis of AF made on the ECG or a Holter. Long term ECG monitoring provides more accurate data on AF incidence.~Administration of flecainide has been shown to be effective in preventing AF and may be useful in preventing these AF episodes after PFO closure.~To the knowledge of the investigators, there is no study assessing the efficacy of any antiarrhythmic drug in the prevention of AF after PFO closure. AFLOAT will be the first randomized study to possibly validate flecainide to prevent AF in these patients.