Stroke patients with cardiac atrial septal abnormalities: differential infarct patterns on DWI

Stroke mechanism in patent foramen ovale (PFO) and/or atrioseptal aneurysm (ASA) remains unclear. We aimed to study the stroke pattern on diffusion weighted imaging (DWI), in cryptogenetic stroke according to septal abnormalities.

We prospectively evaluated 314 cryptogenetic strokes. Patients were categorized according to transesophageal echocardiography (TEE) findings: PFO with ASA, PFO alone, and no abnormalities. The study group consisted of 126 patients with acute DWI lesions within the first 7 days after the stroke onset. We considered the presence of scattered lesions or a cortico-subcortical territorial lesion as highly suggestive of an embolic pattern.

PFO was identified in 77 patients (61%) and no alterations in 49 patients (39%). TEE revealed ASA in 42 patients (54.5% of PFO patients). An "embolic" pattern was depicted in 84 (66.7%) and subcortical in 42 (33.3%). An "embolic" pattern was significantly (P= .01) more frequently seen in PFO with ASA patients (n= 37;44%) as compared to PFO without ASA (n= 22; 26.2%) or no abnormalities (n= 25; 29.8%) on TEE. Univariate analysis revealed that age (P= .06), hyperlipidemia (P= .04), degree of shunt on TEE (P= .002), and the presence of an ASA (P= .008) were associated with an embolic pattern. After adjusting for sex, age, and vascular risk factors, only the presence of PFO, with ASA (OR 7.27; 95% CI 1.5-35.22 P= .014) was independently associated with an embolic pattern.

In patients with cryptogenetic stroke, the presence of PFO with ASA, but not isolated PFO, is associated with an embolic pattern on DWI. These findings provide insights into the patho-mechanism of stroke in patients with PFO.