What if the patient has a PFO?
PFOs are present in up to 25% of the population and in most cases confer little if any stroke risk. Large PFOs with a right-to-left shunt and those with atrial septal aneurysms are of greater concern.
If a concerning PFO is found the next step is to identify a venous source. Pelvic vein MRI may identify DVTs not apparent by standard vascular ultrasound techniques.
PFO closure has been hotly debated: CLOSURE I compared PFO closure to best medical management in subjects with cryptogenic stroke and did not find a benefit of PFO closure after 2 years of follow-up.
Most subjects with recurrent stroke had evidence of a mechanism other than paradoxical embolism.
At this point, PFO closure is best done in the setting of an RCT.
