PFO and paradoxical embolism producing events other than stroke

A patent foramen ovale (PFO) is a risk factor for cerebral events such as cryptogenic stroke, transient ischemic attacks, and migraine headaches. Far less commonly, PFO is associated with non-cerebral, paradoxical systemic embolic events such as myocardial infarction (MI), renal infarct, and limb ischemia. This report details the incidence of systemic paradoxical emboli at our institution.

416 patients were referred for evaluation of PFO related conditions from 2001 to 2009. Clinical history and medical records of the patients were reviewed for incidence of cryptogenic stroke, transient ischemic attack (TIA), migraine headache, arterial desaturation, and noncerebral systemic embolism.

As the primary presenting symptom, 219 patients had a diagnosis of cryptogenic stroke, 38 patients had migraine headaches, and 80 patients had transient neurologic deficits consistent with a TIA or complex headache. Twelve patients (2.9% of the total population) presented with a presumptive diagnosis of systemic embolism. Eight of these patients had acute MI diagnosed by elevated cardiac biomarkers, electrocardiogram changes, and/or imaging evidence of a left ventricular wall motion abnormality, without evidence of obstructive coronary disease on angiography. Four patients had evidence of peripheral embolism to a systemic artery, including the popliteal artery, ophthalmic artery, and brachial artery. PFO closure was performed in 197 patients (47.4% of the total population), including eight patients in the systemic embolism group. All closure procedures were successful.

Although most paradoxical emboli travel to the brain, noncerebral paradoxical embolism is also associated with PFO. In addition to embolism of thrombus, there may be paradoxical passage of vasoactive chemicals that induce intense coronary spasm and myocardial infarction. Diagnosis is often challenging, given the lack of definitive criteria and the need to exclude other potential etiologies.