Background: 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.
Methods: 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.
Results: 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.
Conclusion: 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.