Ventricular Assist Device May Offer Hope for Youngest Heart Patients
(HOUSTON) -- Just prior to her 5th birthday, Avery Toole had her first heart attack.
Avery had told her parents that her stomach was hurting. When her mother Cheryl Toole looked at her, Avery's skin was grayish. They brought her in to the hospital, and almost as soon as she got there, her heart stopped pumping blood.
"To stand there and watch her get chest compressions was shocking and devastating," Cheryl Toole recalled. "It was the first time we thought we might lose her."
It was not the first time Avery's heart had threatened to fail. Born with a rare heart defect in which the left side of her heart was underdeveloped, surgeons undertook heroic efforts when she was an infant. She underwent a total of eight open heart surgeries at Children's Hospital in Boston.
Avery is far from the only child to endure such heart issues. Hundreds of children in the United States are born each year with failing hearts, and often the only hope is transplant. Unfortunately many are not able to survive long enough to find a suitable donor heart. As children's hearts continue to deteriorate, doctors turn to so-called bridging therapies.
One such option is to attach a young patient to a machine that serves the functions of the heart and lungs. Called ECMO, this machine can buy some time for these children -- but it can only be used for short time, and some patients experience grave complications when they are on the machine.
For a while, Avery was one of these patients. Placed on and off ECMO four times after continuing to experience heart attacks, her platelets -- the substance in her blood that allows clotting -- had become dangerously low. She was bleeding into her lungs. She could not survive on ECMO for very much longer.
Not too long ago, ECMO would have been Avery's only option; indeed, it was the only option for these young patients for many years. To Dr. Charles Fraser, this was a huge problem.
"My interest [in this project] related to my clinical frustration," Fraser said. The surgeon-in-chief at Texas Children's Hospital in Houston, Fraser served as principal investigator for The Berlin Heart Study Group. Its goal: to conduct the first prospective, multicenter study of a device that has not been used yet in children.
Largely because of this work, kids with failing hearts have been able to take advantage of a technology that at one time was only available to adults -- Ventricular Assist Devices, or VADs. There have been no FDA approved VAD devices for children until this trial.
"Having been a children's heart surgeon of a number of years, the clinical necessity of this device was obvious," Fraser said.
The study, published in New England Journal of Medicine, compared the outcomes of 48 children who received VADs to those of children who received ECMO in the past. The study divided the patients into groups based on size and showed all children with VADs did better. Smaller patients had a 13 percent increased success rate and larger patients a 25 percent increase success rate.
VAD was not without its complications. About 30 percent of patients with a VAD suffered from a stroke. Most strokes were minor, others were disastrous. Despite this, the adverse events rate was lower with VAD then ECMO.
Cheryl Toole said once Avery had been given a VAD, her situation improved dramatically.
Avery was able to get stronger, and 52 days later a suitable donor was found. Avery received a new heart -- one doctor says she would not have survived long enough to receive it had it not been for her VAD.
"Before the Berlin heart was available there is no question that [Avery] would have not survived," said Dr. Charles Almond, the Harvard surgeon who implanted Avery's Berlin device.
Whether such devices will be available to other kids who could potentially benefit from them depends on research that will commence next year. This is when four new types of pediatric VAD devices will become available in clinical trials through a program called Pumps for Kids, Infants and Neonates -- also known as PumpKIN.
"Our hope as practitioners in this field is that this [data] will turn up the RPMs on devices in this field and that we develop more devices," Fraser said.
But new devices alone will not solve the problem.
"[I]f we could improve donor awareness we would be able to shorten the waiting time for a heart and perhaps we would not get into a situation where the child is getting sicker and needs a VAD while waiting," said Dr. Daphne Hsu, co-director of the Pediatric Heart Center at Montefiore.
Avery, now 8, starts second grade this September. Monday marked the three-year anniversary of the day she received the donated heart of a little boy named Dalton Lawyer, who was hit by a car and killed while riding his bike.
Since then, the Tooles and the Lawyers have become close friends.
"It's a very special, unique relationship," said Cheryl. "It's just wonderful."
Three years after receiving the donated heart that now beats in her chest, Avery plays t-ball, swims and runs. She just returned from a 12-day sleep-away camp designed specially for children who have had open heart surgery.
"You would never know by meeting her that anything was the matter," Cheryl Toole said.
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