What is PFO, Should it be Closed?

Written by: Prof. Dr. Şükrü Akyüz

In the womb, between the right and left atria of the baby’s (foetus) heart, there is normally an opening (hole) through which blood can pass. This is a normal part of the blood circulation of the foetus. In most people, this hole closes by itself after birth because it is no longer needed. However, in some people it remains open. In medical language, this hole is called a patent foramen ovale (PFO), which means “gaping oval hole”.

Since the word “hole” is often used for PFO among non-medical people, the word “hole” will be used instead of “opening” for ease of understanding.

What is the difference between PFO and ASD?

Both of these are types of hole in the chamber between the atria. In ASD, however, there is a pathological partial failure of the tissue forming the chamber. The baby is therefore born with a hole in the heart. PFO, on the other hand, is not a formation defect, i.e. there is no missing tissue. The presence of a PFO alone is not considered a disease. In order for it to be a problem, a clot that has formed elsewhere in the body must also reach the heart. A PFO may be medically important because it allows a clot to pass from the right side of the heart to the left side of the heart and the clot may travel with the blood to the brain and cause a stroke. However, this probability is extremely low. In other words, the fact that a PFO is detected incidentally in a person is of no significance by itself, unless there is a stroke or some other disease picture.

How common is PFO?

PFO is very common; 1 in 4 people have it. This means that 2 billion of the world’s 8 billion inhabitants have PFO.

What causes PFO?

It is not clearly known what causes PFO.

What are the symptoms of PFO?

Most people do not have any symptoms or signs that are directly caused by the PFO. A PFO is often detected by chance during tests for other purposes.

How is PFO diagnosed?

  • ECHO (Echocardiography; heart ultrasound): It is the main test in the diagnosis of PFO. It is an instrument that works by using sound waves. It takes a film of the heart. The hole and the blood escaping through it can be seen directly. However, in most cases it cannot be seen directly. In this case, “contrast echocardiography” is performed. In contrast echocardiography; water containing bubbles is given from the arm vein, these bubbles reach the heart and if PFO is present, it is observed that these bubbles pass from the right side of the heart to the left side.

  • TEE (ECHO through the oesophagus): ECHO through the oesophagus, which is neighbouring the heart, can provide clearer images. For this, a flexible cable with the diameter of a pencil is inserted into the oesophagus. At the end of this cable there is a special mechanism for obtaining images. This allows the size and shape of the opening to be determined in detail. TEE is used to confirm the diagnosis when a PFO is suspected on contrast echocardiography and to guide doctors in the non-surgical closure of the PFO.

  • Transcranial Doppler: It is an instrument that works by using sound waves and water bubbles like contrast echo. However, ultrasound is performed on the skull, not the heart. The aim is to detect water bubbles that pass through the PFO and reach the skull (and therefore the brain) via the blood. If no water bubbles are detected, the PFO is not present. However, if water bubbles are detected, a TEE should be performed to confirm the presence of a PFO.

What are the complications of PFO?

The most important complication of PFO is stroke, i.e. a clot in the brain. Stroke can be permanent or temporary. The temporary one is called TIA (transient ischaemic attack). However, the probability of PFO causing a stroke is extremely low (Remember; if every person with PFO had a stroke, 1 out of every 4 people in the world would have a stroke). In fact, the most common cause of stroke is actually vascular problems such as clots or bleeding. Vascular problems are usually seen in elderly patients. Therefore, if a young person has a stroke, it is more likely to be caused by a PFO than an elderly person. PFO can very rarely cause complications other than stroke:

  • Clot in the heart vessel (heart attack)
  • Thrombosis to organs other than the brain
  • Migraine type headache
  • Air embolism during diving

What should people with PFO pay attention to?

Diving carries a special risk in PFO. However, if the rules of diving are strictly adhered to, PFO does not prevent diving. However, if the rules are not observed, air bubbles in the vein can pass through the PFO and cause various problems.

Is treatment necessary for PFO?

Most people with PFO do not need treatment. Because PFO itself is not considered as a disease. In order for treatment to be necessary, the complications mentioned above must have developed. At this point, most people ask the following question: “So, we cannot take precautions before we have a stroke? Should we wait for a stroke?”. However, it should not be forgotten: In medicine, treatment decisions are always based on a risk-benefit analysis. The better option is always preferred. For example, if the treatment in question is the closure of the PFO, the treatment is either to use blood thinners or to close the PFO non-surgically with umbrella-like devices in addition to the medication. However, medication carries the risk of serious bleeding (brain haemorrhage, stomach haemorrhage, etc.). In the closure process, complications such as heart perforation may develop. Therefore, starting these treatments for every patient with PFO means unnecessarily exposing a person who is extremely unlikely to have a stroke during his/her lifetime to the possible complications of these treatments.

  • Blood thinners: If all other causes of a stroke have been investigated and found to be non-existent, then PFO is considered to be the cause of the stroke. In this case, blood thinners (Coraspin, Ecopirin, Plavix, etc.) are started to prevent re-coagulation.
  • Non-operative closure with a device: This operation is technically very similar to ASD closure. It is performed by interventional cardiologists. A thin, flexible and long tube (catheter) is sent to the heart through the groin vein. The PFO is closed with an umbrella-like closure device that is compressed inside the catheter. It is called a non-surgical method because the heart is not stopped and the rib cage is not cut. Heart surgery is not a preferred method to close the PFO. Because the non-surgical method is much safer.

When is the PFO switched off?

In the event of a stroke (temporary or permanent, mild or severe), other causes of stroke such as stenosis of the carotid artery and heart arrhythmia (atrial fibrillation) are investigated. If the patient does not have any of these causes but has a hole in the heart called PFO, it is assumed that the cause of the stroke is probably clots travelling through this hole to the brain and the PFO is closed.

What is the success rate of PFO closure?

The overall success rate is >95%.

What are the risks of PFO closure?

Like any other interventional procedure, this procedure is not without risks. Significant complications such as dislodgement of the device and clot formation on the device occur in 1 in every 100 people; death occurs in 1 in every 1000 people.

I am concerned about these risks, what should I do?

You may be right to be concerned, but remember: These complications are very rare. The important question is whether the procedure is really necessary. If the decision is made in accordance with current scientific data and guidelines, then avoiding this procedure means that you are exposing yourself to more significant risks (in particular, stroke).

How long does the PFO closure process take?

Usually, 1 hour. However, this time may be shorter or longer depending on the anatomical features of the PFO.

Is the procedure performed by stopping the heart, as in heart surgery?

No, it is not. There’s no need to stop the heart.

Will I feel pain during PFO closure?

No, it is not. The procedure is performed either under sedation or under general anaesthesia. The difference is that under general anaesthesia, a tube is inserted into the patient’s respiratory tract and the patient is supplied with air by a respirator; under sedation, no breathing tube is inserted, the patient is not connected to a respirator, the patient is simply put to sleep and breathes on his/her own. In both techniques, drugs are given to prevent the patient from feeling pain during the procedure. General anaesthesia (intubation) is more comfortable for the patient.

Translated with www.DeepL.com/Translator (free version)

How many days will I stay in hospital after the procedure?

Most patients are discharged the next day.

Is the PFO closure device subsequently displaced?

Although there have been cases reported in the literature where the device was found to have moved afterwards, this is very rare. It is not possible to move the device after it is covered with tissue within a few months.

Will I feel the device in my body?

No.

Will the device stay in my body for life?

Yes. It is not possible to remove the device.

Will I use blood thinners after PFO closure procedure?

Yes. Usually, two blood-thinning medicines are used together for the first few months, one of which is a low-dose aspirin (Coraspin or Ecopirin) and the other is another medicine with the active ingredient clopidogrel. After a few months, one of these is stopped. Then, depending on the neurologist’s recommendation, the same or a different blood thinner is continued for life.