PFO closure after stroke, what the decision involves
A patent foramen ovale is a small flap between the upper chambers of the heart. When closing it may reduce the risk of further stroke.
In short
A patent foramen ovale, or PFO, is a small flap-like opening between the upper chambers of the heart that fails to seal after birth. It is present in roughly a quarter of adults and is usually harmless. It becomes relevant when a stroke occurs in a younger adult and no other cause is found, because a clot may have passed through the opening from the venous circulation to the arterial one. In carefully selected patients, closing the PFO with a catheter-delivered device reduces the risk of a further stroke compared with medication alone.
Call 999 immediately if you develop sudden weakness or numbness on one side, difficulty speaking or understanding speech, sudden loss of vision, or a sudden severe headache. These may be signs of a stroke and treatment is time-critical.
Key facts
- A PFO is common, present in around one in four adults, and in most people has no consequences.
- It becomes clinically relevant mainly after a stroke in a younger adult with no other identified cause.
- Investigation must first exclude other causes, particularly atrial fibrillation, which needs different treatment.
- Benefit is greatest in younger patients with specific anatomical features, assessed by a stroke and cardiology team.
- Closure is performed through a vein in the groin, usually as a day case or with one overnight stay.
What a PFO is
Before birth, blood bypasses the lungs through an opening between the two upper chambers of the heart. After birth, that opening normally seals. In about one in four adults it does not fully close, leaving a flap that can open when pressure on the right side of the heart rises, such as during coughing or straining.
For most people this never causes a problem, and finding a PFO incidentally is not in itself a reason to do anything about it.
Why it matters after a stroke
The concern is paradoxical embolism. A small clot that forms in a vein would normally travel to the lungs and be filtered there. If it passes through a PFO into the left side of the heart, it can travel instead to the brain and cause a stroke.
This becomes a serious consideration when a stroke occurs in a younger adult and a thorough search finds no other explanation. Because a PFO is common, its mere presence does not prove it caused the stroke, and this is the central difficulty in the decision.
The assessment
A rigorous search for other causes comes first, since several of them require quite different treatment. That typically includes brain imaging, imaging of the neck and brain arteries, blood tests, and prolonged heart rhythm monitoring to look for atrial fibrillation, which is treated with anticoagulation rather than with a closure device.
Assessment of the PFO itself uses echocardiography with a bubble study, and usually transoesophageal echocardiography to define the anatomy. Certain features, such as a large shunt or an associated atrial septal aneurysm, are associated with greater benefit from closure.
Scoring systems exist to estimate how likely it is that the PFO was responsible rather than incidental, and these inform a joint decision by a stroke physician and a cardiologist. Randomised trials have shown a reduction in recurrent stroke with closure in selected patients, principally younger adults with high-risk anatomy and no other cause found.
The procedure
Closure is performed through a vein in the groin. A catheter carrying a collapsed double-disc device is advanced to the heart and across the opening. The device is deployed so that one disc sits on each side of the septum, sealing the flap. It is guided by X-ray and echocardiography, usually under sedation or a short general anaesthetic, and takes around an hour.
Most patients go home the same day or after one night. Tissue gradually grows over the device during the following months, and antiplatelet medication is prescribed for a period afterwards.
Recognised risks include bleeding at the access site, a temporary disturbance of heart rhythm, particularly atrial fibrillation in the weeks after the procedure, and, less commonly, device-related complications. Follow-up involves echocardiography to confirm the device is well positioned and the shunt has closed.
Making the decision
This is a decision made jointly rather than a routine recommendation. It involves weighing the estimated likelihood that the PFO caused the stroke, the anatomical features, your age, the alternative of medical treatment alone, and your own view of the trade-off between a one-off procedural risk and a long-term reduction in recurrence. A second opinion is entirely reasonable, and the reasoning behind any recommendation should be explained clearly enough that you can weigh it yourself.
Sources
This page provides general information and does not replace individual medical advice, diagnosis or emergency care. Decisions about tests and treatment depend on your own history, examination and results.