Patent foramen ovale and ischemic stroke: more shadows than lights? What the internist should know

The foramen ovale (FO) is an anatomical structure normally present in the fetus, which can persist in up to 25%-30% of the general population after birth. Normally it does not cause any harm but it has been associated with different pathological conditions; the more frequently encountered in clinical practice is an ischemic stroke or transient ischemic attack without any recognizable cause. However, a causal link between the cerebrovascular event and a right to left shunt through the FO is hard to demonstrate in most cases and which is the best treatment for secondary prevention is still a matter of debate with antithrombotic therapy or transcatheter closure of the FO as possible options. No definitive evidence of which is the most effective treatment is actually available so that a careful evaluation of each single patient is mandatory in order to select who will probably benefit the most from the interventional treatment as opposed to who will reasonably do well with medical therapy alone.