Heart Pumps Work as 'Bridge to Transplant'
Written by Zoe McKnight
To support a failing heart, there are two general types of ventricular assist devices, long-term and short-term.
Two cardiac surgeons – along with four other cardiologists – at St. Paul’s Hospital perform all implantations of long-term devices in the province, under the B.C. Acute Heart Failure Program.
The devices, which are “essentially mechanical heart pumps,” can be used in patients with advanced heart failure, whether from a congenital defect in children or from an infection, heart disease or artery blockages in older people.
“The problem is that if someone gets sick we can’t just pull a heart off the shelf and give it to them,” said cardiac surgeon Dr. Jamil Bashir, who estimates about 100 VAD surgeries are done a year at 10 centres in Canada. The one-year survival rate in adults is now 87 per cent, but it is used to be around 50 per cent.
“Yes, there’s limited donors but also the technology has advanced so much and the results are so good with these pumps, we can put one in when someone really needs support and then wait for the transplant to come.”
Since 2002, when the first VAD was implanted, St. Paul’s has performed 115 of the procedures.
The average patient age is 60; the youngest person outfitted with a VAD at St. Paul’s was 12, and the older 72. Normally about 15 are implanted each year, but last year was a record-breaker at 23.
As of 2012, 123 patients across Canada were waiting for a heart transplant, according to the Canadian Centre for Health Information.
A VAD is known as a “bridge to transplant,” and most often implanted while a patient waits for a suitable organ donor. Others may receive one as a “bridge to recovery,” where the heart needs help pumping blood in order to heal from some other condition.
While high impact sports are not recommended by doctors – patients have even been known to play basketball with a VAD in their heart. They can also fly and drive a car. But patients have to be cautious around water because the electrical cable sticks out of the abdomen.
In Muskaan Grewel, who last year became the youngest-ever patient to receive a VAD anywhere in the world, the cord came out near her stomach and attached to a box contained a small external computer, which she carried around in a backpack that weighed less than two kilograms.
At night, when she was sleeping, she plugged it into a wall in her bedroom. She said the pump whirred “like a bee.”
Grewel was 10 days old when she was diagnosed with dilated cardiomyopathy, a rare condition that weakens and enlarges the heart. Grewel weighed just 19 kilograms when the implant was inserted in the left side of her heart last year. Her heart was the size of an egg.
Other devices, such as a Berlin Heart, have been implanted into patients as young as five months. But the technology is much older and the survival rate not nearly as high as the VAD.
The pump is directly connected to the heart and pumps blood from its left side into the aorta. The blood leaves the pump “in a continuous stream much like water out of a garden hose,” according to HeartWare, the company that makes the new VAD used in Grewal and others at St. Paul’s.
“This continuous flow of blood is different than the pulsing beat of a normal heart, and as a result you may not be able to feel your pulse,” the company states on its online.
Cruder, short-term devices have been around for around 20 years, said Dr. Tim Latham, a cardiac surgeon at Royal Columbian Hospital, which last year fit six patients with short-term ventricular assist devices.
Most of his patients remain in intensive care and do not leave the hospital.
Young patients can be treated at either B.C. Children’s Hospital in Vancouver or Stollery Children’s Hospital in Edmonton, which have an arrangement through the Western Canadian Children’s Heart Network that also services Manitoba. In the last two years, B.C. Children’s performed three VAD procedures.
Published 2013, Vancouver Sun