Abstract WP401: Residual Shunting Post PFO Closure is Associated With Increased Long-term Risk of Recurrent Stroke

Background: Patent foramen ovale (PFO) is an independent risk factor for ischemic stroke, and recent clinical trials have shown long-term benefit of PFO closure. We previously found PFO may increase the risk of stroke due to right-to-left shunting, resulting in venous contamination of arterial circulation, with elevated neurovascular mediators such as homocysteine. However, in clinical practice, residual blood shunting can be observed in ~10% of patients post PFO closure, with unclear significance. Here we prospectively investigated the long-term influence of residual shunting on patient outcome. Method: 1018 PFO stroke patients s/p PFO closure from several medical centers were prospectively recruited in accordance with IRB protocol and followed up to 7 years. Result: While closure rate at our center is much lower (<5%), overall closure rate of patients from all major referral centers range between 5-14%. Patients with compete PFO closure (86%) developed higher event-free probability from recurrent TIA/st...