2006 Stroke Council Award and Lecture—Patent Foramen Ovale and Stroke: What We Have Learned and What We Still Need to Know
Management of patients with cryptogenic stroke and a patent foramen ovale (PFO) is a common clinical dilemma for cardiologists, neurologists, and primary care physicians and is a rapidly growing public health challenge for society. Between 50 000 and 100 000 Americans each year present with a PFO and an ischemic stroke of otherwise undetermined etiology. Collaborative studies by cardiovascular and cerebrovascular physician-scientists over the past 2 decades have advanced our understanding of the epidemiology, pathophysiology, and management of patients with patent foramen ovale and ischemic brain disease. The recurrent stroke rate among young cryptogenic stroke patients with a PFO is modest but higher than normal for age. Coexisting atrial septal aneurysm is a substantial—and the only definite—potentiator of stroke risk in patients with PFO, but PFO size, degree of functional shunting, and coexisting hyper-coagulable state likely are additional risk factors. Pelvic computed tomographic and magnetic resonance venography has improved our ability to detect source venous thromboemboli and underlies new management strategies. Close analysis of randomized clinical trial results suggests that brain imaging demonstration of a superficial convexity stroke location indicative of a highly probable embolic stroke top may usefully guide the selection of anticoagulation versus antiplatelet therapy in medically managed patients. The completion of ongoing randomized clinical trials comparing percutaneous closure devices with medical management is likely to be hastened by the recent withdrawal of humanitarian device exemption approvals and is urgently needed to provide definitive data to guide management of these patients with a linked disorder of heart and brain.