Can stem cells heal heart failure damage?

The CardiAMP trial, underway at University of Colorado Hospital, uses patients’ own bone marrow stem cells in a bid to treat heart failure caused by heart attacks.
January 17th, 2019

In the waning days of 2003, Pete Hagerstrom suffered a heart attack that required quadruple bypass surgery at Memorial Hospital in Colorado Springs (now part of UCHealth). That was a life-changing event for him, of course, as it was for many others in 2003. Nearly 400,000 people in the United States had coronary artery bypass procedures that year.

Hagerstrom made a good recovery from the heart attack, but because of it he is now among the ranks of another large and growing population: the 5.7 million people in the country who have heart failure. Now, however, the 71-year-old Colorado Springs resident is one of a select group helping to study whether patients’ own stem cells can strengthen their failing hearts.

a photo of Pete Hagerstrom at home in Colorado Springs
Pete Hagerstrom, at home in Colorado Springs, is the first patient at UCH to participate in the CardiAMP heart failure trial at UCH. He does not know whether he received bone marrow stem cells or not.

The Phase 3 clinical trial involves a therapy from San Carlos, California-based BioCardia, Inc. dubbed CardiAMP. It targets patients like Hagerstrom whose heart failure developed after a heart attack. These patients must also have significantly weakened left ventricles, as measured by their ejection fraction – a measure of the pumping strength of the heart – despite regular medication management and other treatments. Some 18 sites are participating, including UCHealth University of Colorado Hospital on the Anschutz Medical Campus. Hagerstrom is the first patient enrolled at UCH.

Heal thyself

The idea: extract blood from a patient’s bone marrow, centrifuge it to separate the stem cells, and then use a catheterization procedure to deliver the cells to and inject them into ventricle tissue. The hope, which is strengthened by positive results in the previous trial phase, is that the bone marrow stem cells will encourage growth of heart muscle cells called myocytes, said Dr. Natasha Altman, an advanced heart failure and transplant cardiology specialist who is principal investigator for the CardiAMP trial at UCH.

“The theory has to do with utilizing the property of bone marrow stem cells to cause the cardiac myocytes to reproduce a little bit better and cause some strengthening of heart tissue,” Altman said. “The stem cells are not becoming heart cells; they are helping heart cells develop again.”

The primary outcome measure for the trial is improvement in patients’ six-minute walk distances 12 months after the procedure. “We want to see if patients feel better and can do more with the study treatment,” Altman said.

The study could offer new promise for patients like Hagerstrom, said Dr. John Messenger, an interventional cardiologist at UCH and professor of medicine-cardiology at the University of Colorado School of Medicine. He is the co-investigator with Altman for the CardiAMP trial. Messenger completed two days of training for the procedure and performed it on Hagerstrom last fall.

“It’s a very important project because it extends the treatment options we have for patients with heart failure after a myocardial infarction,” Messenger said. He noted that as of now the only choices for patients whose low ejection fractions fail to improve with medications are left ventricular assist devices (LVADs) or heart transplants, but a large percentage of patients don’t qualify for either of those.

Dr. Natasha Altman leads the CardiAMP trial at UCH.
Dr. Natasha Altman leads the CardiAMP trial at UCH.

“This treatment might allow us to get people down the road without having to move on to more complicated mechanical support or transplant,” Messenger said. “It’s another tool that potentially opens the door to more patients.”

During the procedure in the cardiac catheterization lab, members of Altman’s research team extract bone marrow from the crest of the patient’s hip bone, then spin it rapidly to separate large numbers of pure stem cells. Messenger then threads a catheter bearing a corkscrew-like needle to the ventricle. His team uses echocardiography to locate areas of the ventricle that lie at the edges of scarred tissue, then Messenger inserts the needle into the vessel and injects the stem cells. After the procedure, the patient stays overnight at the hospital for observation while the team examines images of the heart to ensure the procedure didn’t puncture the ventricle or cause any other issues.

Hope – with caution

There are several provisos for the study, Altman said. Patients who meet the initial inclusion criteria must have an echocardiogram and a bone marrow biopsy to determine the potency of the stem cells. BioCardia, she explained, uses an algorithm that projects the ability of the cells to sufficiently strengthen the heart muscle.

Thus far, Altman said, about one-third of prospective trial patients nationally have been screened out. “Their stem cells were not strong enough to produce the effect in the heart tissue that we would hope,” she said.

In addition, the study is randomized. Roughly three in five who meet the screening criteria and undergo the procedure will actually receive the stem cells; two in five will go through all the same steps but will not get the treatment. Patients don’t know which group they are in. At UCH, only Messenger knows who received the treatment and who did not.

Hagerstrom is philosophical about that. “It’s a crap shoot,” he shrugged.

Recovery, then a roadblock

He figures that joining the trial was worth a try. He said he’s had discussions with his cardiologist at Memorial about a heart transplant – he’s not eligible – and an LVAD, which he doesn’t need yet. Meanwhile, he said he works closely with Heather Mazzola, a cardiology advanced practice provider with the Heart Center at UCHealth Memorial Hospital, to improve his overall health. That includes using a CPAP (continuous positive airway pressure) machine to treat his sleep apnea and controlling his diabetes with medications. Hagerstrom said he also exercises regularly at the YMCA with the aim of dropping some weight from his 245-pound frame.

An Air Force veteran, Hagerstrom retired in 1988 and worked a series of jobs, including golf course grounds maintenance, in the years leading up to his heart attack – during which he admits he ignored warning signs like chest pain and shortness of breath. The problems caught up with him one night in late December while he worked at his computer. He said he knew immediately that the pain ripping through his chest was a heart attack. He called 911 and was rushed to Memorial, where a cardiologist opened his blocked artery with a stent. Three days later, he had his quadruple bypass surgery and celebrated New Year’s Day 2004 in the intensive care unit.

Dr. John Messenger performed the CardiAMP procedure on Hagerstrom October 30.
Dr. John Messenger performed the CardiAMP procedure on Hagerstrom October 30.

Hagerstrom said his recovery “went fine” for nearly 15 years. “It slowed me down, but I could do gardening in the spring and fall and shoveling. It just took longer than if I hadn’t had a heart attack. I managed with medications and I had no pain.”

That changed last June when he was struck by atrial fibrillation, an irregular heart rate. “That slowed me down completely,” he said. “If I walked 10 feet I was out of breath.”

Groundbreaker

After a hospitalization at Memorial and tests, he slowly recovered with medication, a defibrillator and help from Mazzola. During a later Heart Center visit, he learned about the CardiAMP study, piquing an occasional interest he’d taken over the years in the potential benefits of stem cell therapy. He agreed to go to UCH to see if he qualified, which he did after a completing a series of imaging tests and blood work, wearing a heart monitor and submitting to the bone marrow biopsy.

The biggest surprise of the actual procedure was seeing what he estimated as 20 people jammed into the cardiac catheterization lab to watch Messenger and his team do their work. “I had no idea,” Hagerstrom said, joking about his “celebrity” status as the first patient at UCH to join the trial.

While he awaits the results of the procedure – if any – Hagerstrom is taking an active role in the study. He attends Memorial’s Heart Failure University, a free course designed to educate heart failure patients about managing their disease. In December he talked to attendees about his experiences with the CardiAMP study.

“I’m a recruiter now,” Hagerstrom said with a chuckle. “I have a feeling I’ll be doing more than one of these talks.”

Hagerstrom isn’t the only one with a personal interest in the trial. Messenger’s late father, who was a cardiologist for 40 years in Long Beach, California, participated in an early-phase cardiac stem cell trial at Scripps Health in 2010.

“He realized there could be other options for heart failure treatment, so he was willing to be an early clinical trial participant,” Messenger said. “It’s been an interest of ours in the interventional cardiology realm for some time to try to figure out if there are things we could do to deliver stem cells that could heal the heart.”

As for Altman, she said she’s hopeful that the trial will produce evidence that stem cell therapy can improve the quality of life for heart failure patients without having to resort to more invasive and disruptive interventions.

“I work in the world of LVADs and heart transplants,” she said. “Using patients’ own stem cells for treatment could be a wonderful option.”

Patients who are interested in the CardiAMP trial should contact Alisha Shudy, Professional Research Assistant: alisha.shudy@ucdenver.edu. Referring providers should contact Natasha Altman: natasha.altman@ucdenver.edu.

 

About the author

Tyler Smith is a freelance writer based in metro Denver.