The purpose of the study is to collect more data about performance and safety of the device called "IrisFITTM PFO occluder". This data will be used to help more patients who will accept treatment with this device in the future.

Patients will undergo routine examination, procedure and follow-up. Related data will be collected and kept in a way that patient info is well protected.

This is a Post Market Clinical Follow-up study. Informed consent will be obtained from the patient or from a legally authorized representative of the patient at screening. The patients will be screened (pre-procedure) to determine eligibility for the study. At screening, patients will be assessed for study eligibility by the inclusion/exclusion criteria through their medical history, demographics and transthoracic echocardiography (TTE). Participating patients will have their PFO closed using the IrisFITTM PFO Occluder device. The patients will undergo a clinical examination, electrocardiogram (ECG), clinical laboratory assessment and transthoracic echocardiography (TTE). All periprocedural procedures will be performed according to site´s standard of care.. The efficacy and safety of the devices will be assessed by ECGs, vital signs, physical examination and TTE, which will be done at 1day, at 1month and at 6 months post procedure. Safety will also be assessed at 12 months by telephone visit.

Inclusion Criteria:

• Patients who are according to current international or local guidelines (and future revisions) and per physician discretion scheduled for interventional treatment of PFO.
• Patients who are willing and capable of providing informed consent and participating in all testing/or follow procedure associated with this study.
• Patients who are eligible for treatment with IrisFIT PFO occluder device. (Per physician discretion and device IFU).

Exclusion Criteria:

• PFO tunnel length <1 mm
• Women of childbearing potential who are or plan to become pregnant during the time of the study (method of assessment upon physician's discretion)
• Patients who are currently enrolled in another investigational study or registry that would directly interfere with the current study.