Patent Foramen Ovale Management

Introduction

Patent foramen ovale (PFO) is a hole in the heart that can increase the risk of stroke, and its management involves a comprehensive approach, including diagnosis, risk stratification, and treatment, as recommended by the American Heart Association 1 and the American College of Cardiology 2.

Elevated right atrial pressure promotes right-to-left shunting through the PFO, increasing the risk of paradoxical embolism, as stated by the American Heart Association 3.
Right-to-left shunting through PFO can be assessed by evaluating for evidence of right-to-left shunting, which indicates higher risk, as stated by the Journal of the American College of Cardiology 4.

Venous thrombi can cross from right to left atrium through the PFO, bypassing pulmonary filtration, according to the American College of Cardiology 3, 2.
Risk of systemic embolization to brain (stroke/TIA), coronary arteries, or peripheral circulation exists in patients with PFO, as reported by the American Heart Association 2.
Simultaneous pulmonary and systemic embolism can occur in patients with PFO and deep vein thrombosis, as noted by the American College of Cardiology 2.

PFO is found in approximately 40-45% of younger patients (<55 years) with cryptogenic stroke versus only 14-15% in those with known stroke causes, according to the American Heart Association 5, 4.
In older patients (>55 years), PFO is present in about 28% of cryptogenic stroke cases versus 12% in strokes of known cause, as stated by the American College of Cardiology 4.
Annual recurrent stroke rates in patients with PFO range from 1.5-12% depending on population characteristics, as reported by the American College of Cardiology 4.

For patients with large PFO, evidence of significant right-to-left shunting, and persistent tachycardia, PFO closure plus antiplatelet therapy should be strongly considered, as recommended by the International Stroke Society 6.
Closure is particularly indicated if: Age ≤60 years, History of confirmed non-lacunar embolic stroke or TIA with positive neuroimaging, and PFO is determined to be the most likely cause of any previous embolic events, according to the International Stroke Society 6.
The following table summarizes the recommendations for PFO closure and medical therapy:

Age	PFO Closure	Antiplatelet Therapy	Anticoagulation Therapy
≤60 years	Considered if specific criteria are met	Recommended	Considered if other indications are present
>60 years	Not recommended	Recommended	Considered if other indications are present
No stroke history	Less indicated	Considered	Considered if other indications are present

If PFO closure is not performed, antiplatelet therapy (typically aspirin 81-325mg daily) is recommended for patients ≤60 years, as stated by the International Stroke Society 6.
Antiplatelet therapy, typically aspirin 81-325mg daily, is recommended as first-line treatment for patients with TIA and PFO, as stated by the Canadian Stroke Best Practice Recommendations and the American College of Cardiology 6, 1, 8.
Anticoagulation may be considered for patients with hypercoagulable states or venous thrombosis, according to the American Heart Association 9.
Adding warfarin (INR 2-3) to aspirin may be considered for patients with recurrent cerebral ischemic events despite antiplatelet therapy, with a strength of evidence based on clinical trials 8, 9.

Pregnant patients with a patent foramen ovale (PFO) should be monitored for potential complications including paradoxical embolism and stroke, which occur more frequently during pregnancy due to the hypercoagulable state, as recommended by the European Society of Cardiology 10.
Regular cardiac evaluation should be performed to monitor for signs of right heart failure, atrial arrhythmias, or tricuspid regurgitation in pregnant women with known PFO, according to the European Heart Journal 10.
Neurological assessment should be conducted to be vigilant for symptoms of TIA or stroke (focal weakness, speech disturbance, visual changes) in pregnant women with PFO 10.
Antiplatelet therapy, typically aspirin 81-325mg daily, is recommended as first-line treatment for pregnant women with PFO, as suggested by the European Heart Journal 10.
Anticoagulation should be considered for patients with hypercoagulable states, evidence of venous thrombosis, or recurrent cerebral ischemic events despite antiplatelet therapy, as recommended by the European Heart Journal 10.

Continue monitoring for the hypercoagulable state, which persists for 6-12 weeks postpartum, as recommended by the European Society of Cardiology and the European Heart Journal 10.
Antiplatelet/anticoagulation therapy should be continued as indicated based on pre-pregnancy risk factors, as recommended by the American College of Cardiology and the European Heart Journal 10.
Follow-up imaging, including echocardiography, should be considered 3-6 months postpartum to reassess PFO status, as suggested by the American Heart Association and the European Heart Journal 10.

The American Heart Association recommends structured follow-up after PFO closure to monitor for complications and device function, with a follow-up schedule that includes clinical evaluation and echocardiography at 1, 6, and 12 months post-procedure, and annual follow-up thereafter 6.
Patients with large PFO shunts (>30 microbubbles) require close monitoring, as do those with a history of multiple stroke/TIA events before treatment, and patients with hypercoagulable states, according to the International Journal of Stroke guidelines 6.
Echocardiography is recommended to assess device position and stability, residual shunting, and development of atrial septal aneurysm after PFO closure, with a strength of evidence level of moderate to high 6.
Regular neurological follow-up is necessary to monitor for recurrent symptoms 6.
Periodic reassessment of vascular risk factors is essential for patients with TIA and PFO 6.

Recommending PFO closure in patients >60 years despite evidence showing lack of benefit is considered overtreatment, as stated by the Canadian Stroke Best Practice Recommendations and the American College of Cardiology 6.
Assuming PFO causality in older patients, when the PFO is more likely to be incidental rather than causal for the stroke/TIA event, should be avoided, with a strength of evidence based on clinical trials 6.
Neglecting other stroke etiologies and not performing a comprehensive evaluation for other causes of TIA is a common pitfall, according to the Canadian Stroke Best Practice Recommendations and the American College of Cardiology 6, 11.
Routine surveillance imaging for incidental PFO is not recommended, and no specific follow-up echocardiography is required for incidental small PFO, as stated in the ACC/AHA Appropriate Use Criteria 7.