British girl's heart heals (new type of transplant)

[Solauren]

British girl's heart heals itself after revolutionary transplant

The Canadian Press
British girl's heart heals itself after revolutionary transplant
Provided by: The Canadian Press
Written by: Maria Cheng, THE ASSOCIATED PRESS
Jul. 13, 2009

LONDON - British doctors designed a radical solution to save a girl with major heart problems in 1995: they implanted a donor heart directly onto her own failing heart.

After 10 years with two blood pumping organs, Hannah Clark's faulty one did what many experts had thought impossible: it healed itself enough so that doctors could remove the donated heart.

But she also had a price to pay: the drugs Clark took to prevent her body from rejecting the donated heart led to malignant cancer that required chemotherapy.

Details of Clark's revolutionary transplant and follow-up care were published online Tuesday in the medical journal Lancet.

"This shows that the heart can indeed repair itself if given the opportunity," said Dr. Douglas Zipes, a past president of the American College of Cardiology. Zipes was not linked to Clark's treatment or to the Lancet paper. "The heart apparently has major regenerative powers, and it is now key to find out how they work."

In 1994, when Clark was eight months old, she developed severe heart failure and doctors put her on a waiting list to get a new heart. But Clark's heart difficulties caused problems with her lungs, meaning she also needed a lung transplant.

To avoid doing a risky heart and lung transplant, doctors decided to try something completely different.

Sir Magdi Yacoub of Imperial College London, one of the world's top heart surgeons, said that if Clark's heart was given a time-out, it might be able to recover on its own. So in 1995 Yacoub and others grafted a donor heart from a five-month-old directly onto Clark's own heart.

After four and a half years, both hearts were working fine, so Yacoub and colleagues decided not to take out the extra heart.

The powerful drugs Clark was taking to prevent her from rejecting the donor heart then caused cancer, which led to chemotherapy. Even when doctors lowered the doses of drugs to suppress Clark's immune system, the cancer spread, and Clark's body eventually rejected the donor heart.

Luckily, by that time, Clark's own heart seemed to have fully recovered. In February 2006, Dr. Victor Tsang of Great Ormond Street Hospital in London, Yacoub and other doctors removed Clark's donor heart.

Since then, Clark - now 16 years old - has started playing sports, gotten a part-time job, and plans to go back to school in September.

"Thanks to this operation, I've now got a normal life just like all of my friends," said Clark, who lives near Cardiff.

Her parents marvelled at her recovery, and said that at one point during Clark's illness, they were told she would be dead within 12 hours.

Miguel Uva, chairman of the European Society of Cardiology's group on cardiovascular surgery, called Clark's case "a miracle," adding that it was rare for patients' hearts to simply get better on their own.

"We have no way of knowing which patients will recover and which ones won't," Uva said.

Still, transplants like Clark's won't be widely available to others due to a shortage of donor hearts and because the necessary surgeries are very complicated. In the last few years, artificial hearts also have been developed that can buy patients the time needed to get a transplant or even for their own heart to recover.

Zipes said if doctors can figure out how Clark's heart healed itself and develop a treatment from that mechanism, many other cardiac patients could benefit.

At the moment, doctors aren't sure how that regeneration happens. Some think there are a small number of stem cells in the heart, which may somehow be triggered in crisis situations to heal damaged tissue.

Experts said Clark's example is encouraging both to doctors and patients.

"It reminds us that not all heart failure is lethal," said Dr. Ileana Pina, a heart failure expert at Case Western Reserve University and spokeswoman for the American Heart Association. "Some heart failure patients have a greater chance of recovery than we thought."
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On the Net: www.lancet.com

Wow. The only side effect was a mild tumor, and her heart is back in working condition.

I wonder if this would work using an artificial heart instead of a living heart?

[Melchior]

I wonder if this would work using an artificial heart instead of a living heart?

No, current artificial hearts cannot keep someone alive long enough.

[GrandMasterTerwynn]

Wow. The only side effect was a mild tumor, and her heart is back in working condition.

I wonder if this would work using an artificial heart instead of a living heart?

Mild? The phrases "malignant tumor," and "required chemotherapy," do not belong in the same sentence as the word "mild." Though, in the case of this particular patient, it seems the cancer would've turned up if she had a conventional heart transplant, and would've killed her, since she'd have been completely reliant on the donor heart.

[Solauren]

Don't even presume to lecture me about cancer and chemo-therapy.

Having watched my grandmother go through it for Lung Cancer (surviving onwards of 7 years now, how I'll never know), my uncle A.J go through Bone Cancer (killed him 3 months after the tumour first appeared, right before my cousins wedding), a cancer scare with my mom (nope, but she needed something else done), and several family friends go through cancer, chemo, and occasionally death (i.e my mom's best friend died of Lung Cancer), I can damn well say this;

If all she needed was chemo, and her heart is working as a part of the deal, it's 'mild'. Get back to me when she has multiple tumours in several major organs.


Now then, back on topic....

With Artificial hearts, is it the hearts don't last that long, or the person doesn't last that long that would be a big factor?

[Melchior]

Don't even presume to lecture me about cancer and chemo-therapy.

Having watched my grandmother go through it for Lung Cancer (surviving onwards of 7 years now, how I'll never know), my uncle A.J go through Bone Cancer (killed him 3 months after the tumour first appeared, right before my cousins wedding), a cancer scare with my mom (nope, but she needed something else done), and several family friends go through cancer, chemo, and occasionally death (i.e my mom's best friend died of Lung Cancer), I can damn well say this;

If all she needed was chemo, and her heart is working as a part of the deal, it's 'mild'. Get back to me when she has multiple tumours in several major organs.

Your personal experience, while sad, has no scientific value whatsoever. "Mild" isn't an appropriate adjective, even if she seems to be healthy, now. One of the more important roles of the immune system is to keep watch against neoplastic cells, if it's suppressed to avoid rejection, the patient's chances of developing cancer increase (this is a simplification, but it's reasonably accurate).

With Artificial hearts, is it the hearts don't last that long, or the person doesn't last that long that would be a big factor?

The person doesn't last. Artificial hearts are biomechanically suboptimal for a variety of reasons and, with time, will kill the patient; at the moment even new, more advanced models are investigated basically only as a stopgap measure while waiting for a transplant.

[Broomstick]

With Artificial hearts, is it the hearts don't last that long, or the person doesn't last that long that would be a big factor?

The biggest problems are blood clots and failure of the artificial heart itself, but strokes and hemorrhage (from necessary anti-coagulants to prevent blood clots) are also a risk. As current artificial hearts also require external connections risk of infection is also an ever-present danger.

The person doesn't last. Artificial hearts are biomechanically suboptimal for a variety of reasons and, with time, will kill the patient; at the moment even new, more advanced models are investigated basically only as a stopgap measure while waiting for a transplant.

On the other hand, a few patients on artificial heart support (where there is a pump supplementing heart function) have recovered sufficiently to not need a transplant. An assistive pumping device has also become sort of standard after some heart surgeries (my mom had one after her second heart surgery for a time) in order to reduce the burden on a traumatized heart in order to assist healing. Certainly, these are good things, but we're not at the point of having a truly reliable, self-contained artificial heart such as Captain Picard had in TNG. That is why we still perform heart transplants - we have not built anything that matches the function of a natural human heart.

[Shroom Man 777]

I wonder why artificial hearts are never as good as natural ones, from those factors Broomy mentioned. Maybe it's because artificial hearts just... pump? While natural hearts actually receive all those biological feedback mechanisms and chemical regulatory whatsits from the body and respond by, say, increasing or decreasing the heart rate, etc? Or is it just maybe because the artificial hearts aren't organic and squishy like real hearts, and hence blood ends up coagulating inside their chambers and stuff?

[Broomstick]

I wonder why artificial hearts are never as good as natural ones, from those factors Broomy mentioned. Maybe it's because artificial hearts just... pump? While natural hearts actually receive all those biological feedback mechanisms and chemical regulatory whatsits from the body and respond by, say, increasing or decreasing the heart rate, etc?

I doubt that's it - after all, we have artificial pacemakers that do that long term with few if any complications. Granted, they aren't as fine-tuned as natural heart rhythm systems but that's improving rapidly.

Or is it just maybe because the artificial hearts aren't organic and squishy like real hearts, and hence blood ends up coagulating inside their chambers and stuff?

^ This. Artificial heart values have similar, if less severe problems. Heart valve recipients are put on anti-coagulants for life, and are still at an elevated risk of clots and strokes.

There is significant difficulty in making a pump whose component parts won't trigger an immune reaction, won't lead to blood pooling in nooks and crannies and leading to clots, with the required flexibility and endurance to do the job long term. Organic hearts not only do all the above, but their cells undergo constant maintenance and turnover which means they are under constant low level repair, unlike inorganics which are not self-repairing. I don't think we have a man-made pump anywhere that can be expected to cycle 70-100 times a minute continuously for 70-100 years with no external maintenance - but a healthy natural heart does just that. And, oh yes, a natural heart uses a MUCH smaller power source (actually, multiple tiny power sources working together) than any artificial heart to date.

[Melchior]

On the other hand, a few patients on artificial heart support (where there is a pump supplementing heart function) have recovered sufficiently to not need a transplant. An assistive pumping device has also become sort of standard after some heart surgeries (my mom had one after her second heart surgery for a time) in order to reduce the burden on a traumatized heart in order to assist healing. Certainly, these are good things, but we're not at the point of having a truly reliable, self-contained artificial heart such as Captain Picard had in TNG. That is why we still perform heart transplants - we have not built anything that matches the function of a natural human heart.

Yes, but you're talking about rather different devices, and, obviously, the patient's heart need to be in relatively acceptable conditions in order to be able to function in synergy with assistive pumps (of which, truth to be told, new designs are also currently being tested, IIRC).

[frogcurry]

I wonder why artificial hearts are never as good as natural ones, from those factors Broomy mentioned. Maybe it's because artificial hearts just... pump? While natural hearts actually receive all those biological feedback mechanisms and chemical regulatory whatsits from the body and respond by, say, increasing or decreasing the heart rate, etc? Or is it just maybe because the artificial hearts aren't organic and squishy like real hearts, and hence blood ends up coagulating inside their chambers and stuff?

One factor that has been identified in studies of their use is that they need to provide surges of pressure (i.e. positive displacement) as per a natural heart. Continuous pressure like a typical centrifugal pump wants to give you is bad in the human body and was found to lead to a much higher stroke risk in those who were supported on them. The high-low pressure cycle through your blood vessels seems to be expected by your body and so is required to be replicated somewhat. I'm not aware of how many articifial heart devices are continuous pressure versus those that are positive displacement or how closely the current generation match the human heart pressure cycle though.

[TheLostVikings]

One factor that has been identified in studies of their use is that they need to provide surges of pressure (i.e. positive displacement) as per a natural heart. Continuous pressure like a typical centrifugal pump wants to give you is bad in the human body and was found to lead to a much higher stroke risk in those who were supported on them. The high-low pressure cycle through your blood vessels seems to be expected by your body and so is required to be replicated somewhat. I'm not aware of how many articifial heart devices are continuous pressure versus those that are positive displacement or how closely the current generation match the human heart pressure cycle though.

One of my friends father has had one of those continuous pressure pumps temporarily installed while waiting for a heart, leaving him with no pulse(!). He said it took a really long time to get used to the "silence" as he usually describes it.