Brain saved by a closed hole in the heart

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"I don't go around worrying. But it's good to know that I've done everything I can not to have another stroke," says Malin. The cardiologist Magnus Settergren has closed a small hole in his heart. Recent research indicates that this will reduce the risk of what happened last spring happening again.

Malin was at a forty-year birthday party at Berns, walking up some stairs, when something that felt like a wave went through her brain.

"I stopped right in the middle of a chat with a former colleague. She saw that half of my face was drooping and tried to get me to say a few words. But I couldn't get anything out."

Malin Tikkakoski, 32 years old, had just had a TIA, a transitory ischaemic attack. This refers to a clot in the brain which, unlike a full stroke, quickly disperses and disappears.

"It was over in three minutes, but there was an incredible tingling in half my body. At first I didn't worry about it. It never occurred to me that I could have had a stroke at 32, but my colleague insisted that I should go to the hospital.

Malin had been lucky. A TIA does not cause any permanent damage and so it is sometimes called a warning stroke. Following investigation at Karolinska and a short time off work, she was able to go back to her everyday life of working and picking up her kids from the nursery. Six months later she is back at hospital for an operation on her heart which is intended to reduce the risk of another stroke.

"There are patients who have a stroke for apparently no reason. They don't have the usual risk factors, such as smoking, diabetes or high blood pressure,", says Christina Sjöstrand, a neurologist at Karolinska University Hospital and an associate professor at Karolinska Institutet.

Why they are affected is as yet unclear. We call this type of stroke a "cryptogenic" stroke. An unusually high number of people who have had a cryptogenic stroke have been found to have an opening between the two atria of their hearts, known as patent foramen ovale (PFO). There have been theories that a blood clot can form on the venous side that finds its way to the arterial side via the PFO and on to the brain, where it causes a stroke. However, previous studies have not been able to provide any definite answers as to whether the risk of a new stroke can be reduced by closing the hole.

"Everyone has this opening in their hearts before they are born, but in most people it closes when we take our first breaths," explains Magnus Settergren, a cardiologist at Karolinska University Hospital and an associate professor at KI.

One in four people still have this hole for the rest of their lives, often without causing any problems, because the function of the heart is not affected.

In the spring of 2017, three articles were in published in the highly regarded medical journal "New England Journal of Medicine", all of which reported benefits from closing the opening in patients such as Malin Tikkakoski. Christina Sjöstrand and Magnus Settergren are co-authors of the studies. They show that young people without any of the classic risk factors, but who have a PFO and who have had a stroke, are at three times the risk of having another stroke unless the hole is closed.

Christina Sjöstrand

"This is new. There hasn't been any convincing evidence before now," says Christina Sjöstrand.

The team monitors the operation via ultrasound and X-ray images, and the procedure usually takes about half an hour.

Magnus Settergren believes that the guidelines for treating this group of patients will probably be changed.

Magnus Settergren

"I think that about a hundred stroke patients a year in the Stockholm county region could benefit from closure. What is important to know is that not everyone with PFO is also at an increased risk of stroke," he adds.

"Only those who have had a stroke are candidates for closure. There is no support for this procedure as a preventive measure. Why some people with a cavity between the heart's atria are affected by stroke and not others is one of the questions we want to study further," says Christina Sjöstrand.

Every other week, a team consisting of a neurologist, a cardiologist, a neuroradiologist and a clinical physiologist meets to discuss younger stroke and TIA patients with PFO that are potential candidates for closure. PFO (patent foramen ovale) is an opening between the two atria in the heart.

Text: Catarina Thepper, Photo: Stefan Bolin

Facts about the study

The research has involved a lot of employees, including from Theme Neuro and Theme Heart & Vascular at Karolinska University Hospital: Kosta Kostulas, Maria Lantz, Tatyana Bazjenova, Eva Mattsson, Per-Hermann Jacobsen and others.

A total of 664 adult patients were included, of whom 60 were from Stockholm County. All of them were young and in good physical condition and they had suffered inexplicable blood clots in the brain.

The study was randomised. The patients were randomly assigned to having the hole closed in combination with thrombocyte-inhibiting therapy or just thrombocyte-inhibiting medication.

The follow-up was over a three-year period. The results show that 1.4 percent of the patients on the combination therapy had another ischaemic stroke at some point during the following 24 months. In the group that was only given thrombocyte-inhibiting therapy, it was 5.4 percent.