Background: The frequency of patent foramen ovale (PFO) is greater in patients who have had a stroke and transient ischemic attack (TIA) than that in the general population. However, it is not well defined, which PFO would cause stroke or TIA. In this trial, we aimed to evaluate whether there was a difference regarding morphologic features of PFO in patients who were symptomatic (cryptogenic stroke or history of TIA) or asymptomatic according to the neurologic findings.

Methods: Symptomatic patients with PFO and cryptogenic stroke or TIA and asymptomatic patients with PFO who were symptomatic in terms of neurologic findings as well as patients without any neurologic symptoms in whom PFO was diagnosed incidentally by transesophageal echocardiography were enrolled to this retrospective study on the condition that they were aged younger than 55 years. Not only the clinical and demographic characteristics of 2 groups were compared but also their morphological features were assessed. The morphologic features of PFO that were assessed included the length and height of tunnel, atrial septal excursion distance, thickness of septum primum, and thickness of septum secundum.

Results: One hundred fifty-six patients, 64 of whom were symptomatic, were enrolled to this study. The height of PFO (median, 3.0 [interquartile range, 2.0-3.8]mm versus 2.0 [2.0-2.0]mm, P < .001), thickness of septum secundum (5.0 [5.0-7.0] versus 3.0 [2.0-3.0], P < .001), and septal excursion distance (7.0 [6.0-10.5] versus 4.0 [4.0-5.0], P < .001) were found to be greater in the symptomatic group than those in the asymptomatic group. There was no significant difference regarding the length of tunnel and thickness of septum primum. The ratio of length to height of PFO tunnel was less in the symptomatic group (3.0 [3.0-3.23] versus 5.0 [4.0-6.25], P < .001).

Conclusions: Our findings appear to indicate that a higher PFO tunnel, relatively greater interatrial septal mobility, thicker septum pellucidum, and the presence of an atrial septal aneurysm may help identifying the subjects at the age of or younger than 55 years with PFO who are at greater risk for cryptogenic stroke or TIA.