Neuroimaging findings in cryptogenic stroke patients with and without patent foramen ovale

Patent foramen ovale (PFO) and cryptogenic stroke are commonly associated but some PFOs are incidental. Specific radiological findings associated with PFO may be more likely to indicate a PFO-related cause. We examined whether specific radiological findings are associated with PFO among subjects with cryptogenic stroke and known PFO status.

We analyzed the Risk of Paradoxical Embolism(RoPE) Study database of subjects with cryptogenic stroke and known PFO status, for associations between PFO and: (1) index stroke seen on imaging, (2) index stroke size, (3) index stroke location, (4) multiple index strokes, and (5) prior stroke on baseline imaging. We also compared imaging with purported high-risk echocardiographic features.

Subjects (N=2680) were significantly more likely to have a PFO if their index stroke was large (odds ratio [OR], 1.36; P=0.0025), seen on index imaging (OR, 1.53; P=0.003), and superficially located (OR, 1.54; P<0.0001). A prior stroke on baseline imaging was associated with not having a PFO (OR, 0.66; P<0.0001). Finding multiple index strokes was unrelated to PFO status (OR, 1.21; P=0.161). No echocardiographic variables were related to PFO status.

This is the largest study to report the radiological characteristics of patients with cryptogenic stroke and known PFO status. Strokes that were large, radiologically apparent, superficially located, or unassociated with prior radiological infarcts were more likely to be PFO-associated than were unapparent, smaller, or deep strokes, and those accompanied by chronic infarcts. There was no association between PFO and multiple acute strokes nor between specific echocardiographic PFO features with neuroimaging findings.