Patent Foramen Ovale Closure—Addressing the Unmet Need for Reducing the Risk of Ischemic Stroke

Abstract

Cryptogenic stroke—that is, stroke of an undefined origin, despite thorough investigation—is relatively common, accounting for around one-quarter of cerebral ischemic events. People under 55 years of age are relatively more likely to experience cryptogenic stroke than older individuals. In many patients, the presence of a patent foramen ovale (PFO) may contribute to the risk of cryptogenic stroke; a PFO allows dislodged venous thrombi to pass from the right atrium to the left atrium. This is the basis of paradoxical embolism, and the resulting cerebral artery occlusion may lead to stroke. Treatment to reduce the risk of recurrent cryptogenic stroke uses antithrombotic agents and, increasingly, the interventional option of PFO closure using a catheter-based closure device. Following early clinical trials, the benefit of PFO closure was relatively uncertain. Emerging evidence from longer-term studies published in recent years, however, has presented a clear case for the benefits of PFO closure in selected patients under the age of 60 years in terms of reducing risk of recurrent stroke. Treatment guidelines are being updated to reflect these findings.