Scientists say it’s irrefutable: stem cells do help repair heart cells damaged by heart attack and disease
After over 10 years of experimental research on the use of stem cells to repair heart cells damaged by heart disease and heart attack, scientists now say there’s enough evidence to say they are effective. And the search is now on to find the best stem cell type for this type of therapy.
Heart disease has been the world’s top killer for many years now. About 17.3 million people across the world died from cardiovascular diseases in 2008 — a large portion of this number from heart disease.
In the United States alone, 4.8 million people suffer from congestive heart failure — a condition in which damage to heart muscle cells causes the heart to pump less effectively — and each year, there are 400,000 new cases. Heart attack, which occurs in nearly 1.1 million Americans, is one major contributor to heart failure.
For those suffering from this common but deadly disease, stem cell research represents a new medical frontier. And over the past 10 years or so, scientists have been researching how to use stem cells to replace damaged heart cells and to restore heart function practically.
Now scientists say it isn’t anymore a question of whether using stem cells help with heart disease — but a question of which type of stem cells to use and what processes and techniques are more effective.
“It’s no longer a question of whether the bone marrow cells work or don’t work; they do work when you have healthy stem cells,” Dr. James Willerson — president of the Texas Heart Institute, a world-renowned cardiologist and a pioneering expert on stem cells for heart disease research — tells Reuters Health in an interview. “The search now is to find the very best stem cell type or types,” he says.
A former chairman of both the National American Heart Association Research Committee and the Cardiovascular and Renal Study Section of the National Institutes of Health, Dr. Willerson has been doing research on bone marrow-derived stem cell transplantation for severe heart failure since 2001.
He’s has lectured and served as visiting professor at more than 220 institutions worldwide, has published more than 850 scientific articles, and received numerous awards, including the James B. Herrick Award from the American Heart Association (1993) and the American College of Cardiology’s Distinguished Scientist Award (2000).
Dr. Willerson led one of two stem cell studies that were presented at last month’s 26th American College of Cardiology (ACC) meeting. Both studies showed that stem cells derived from the bone marrow of heart failure patients and injected into their hearts produced significant improvement in the pumping function of their heart’s left ventricle.
The two studies were presented at the ACC’s annual meeting in Chicago on March 26. Dr. Willerson led the study done by researchers from the Texas Heart Institute, while San Diego-based Stemedica Cell Technologies Inc. — a biotech company that produces allogeneic adult stem cells and stem cell factors for the use of research institutions and hospitals, conducted the other study.
In his study, Dr. Willerson found that stem cells derived from a patient’s bone marrow helps treat severe heart failure — but the results are even better when stem cells are taken from fat.
Meanwhile, Stemedica’s study showed that treatment with a new form of stem cells it developed in its labs — ischemic tolerant mesenchymal stem cells (itMSC) — improved cardiac function in 92 heart attack patients. The trial was undertaken by Dr. Daniyar Jumaniyazov and Dr. Nikolai Tankovich, Stemedica’s chief medical officer.
In heart disease, stem cells point the way
The heart works as a muscle, and when heart attack occurs, this muscle suffers massive damage — great slabs of tissue die, many vessels are killed, and muscles and vessels need to be replaced. In a heart attack, some of the heart’s muscle is cut off from its oxygen supply and cells start to die within seconds.
Seeing the change as a trauma, the body’s immune system begins to wall off the dying tissue — creating an ever-thickening layer of scarring. Over time, the scar tissue hampers the heart’s ability to pump blood efficiently throughout the body. Thus, the Holy Grail of heart attack research is: reversing scarring and maintaining as much healthy, and active, heart muscle as possible.
Right now, the drugs used to treat heart disease work by protect this muscle from working too hard. But stem cell therapy offers a chance of actually regenerating the damaged or diseased heart muscle and tissue.
And so far, the findings of many studies — including the two recent ones presented during the cardiologists’ meeting — are promising.
itMSCs regenerate heart muscles
Commenting on the first of the two studies presented during the ACC meeting — that which showed Stemedica’s itMSCs improved cardiac function significantly in heart attack survivors — Dr. Nabil Dib, associate professor of medicine at the University of California, San Diego and Clinical Cardiovascular Cell Therapy director said:
“Data from this early clinical trial are very promising. If these results continue as patients are followed longer term, and if they can be replicated in a larger clinical trial, then Stemedica’s itMSCs stem cells may well play an important role in the treatment of heart disease.”
“These are impressive results and provide a great deal of hope for patients with heart disease,” says Dr. Jackie See, an interventional cardiologist specializing in stem cell research in Fullerton, California, in a press release from Stemedica.
“Stents open up the narrowed blood vessels. With the addition of stem cells, we can potentially rescue some damaged myocardial cells, promote new blood vessel growth, decrease inflammation, and strengthen the damaged muscle,” Dr. See explained.
“I can see a day in the near future when intravenous itMSC administration becomes part of the standard of care following an acute myocardial infarct,” she added.
In the Stemetica-sponsored study, 45 heart attack survivors underwent reperfusion by stent. After being carefully matched with donors, they were divided into a treatment and a control group. On the seventh day after their heart attacks, the treatment group received intravenous infusion of Stemedica itMSCs while the control group received normal saline solution.
After three months, the left ventricles of the hearts in patients in the treatment group showed an 11-point improvement in the ejection fraction, compared to those who received standard care. More importantly, this improvement led them to regain a normal level of ejection fraction. Ejection fraction or EF is the amount of blood pumped with each heart contraction. It’s an important measurement in determining how well the heart is pumping out blood and is used to diagnose and track heart failure.
By comparison, the control group showed a level of improvement expected with standard care — but their EF remained below normal.
The stem cell treatment group also experienced lower levels of C-reactive protein and BNP — two blood markers of inflammation — indicating a significant improvement. They also showed improvements in the quality of life indicators.
The health improvements were confirmed when magnetic resonance imaging (MRI) performed on day six and again day 30 showed significant decreases in lesion size. Patients in this study will be followed for one year.
The Stemetica study, a placebo-controlled blinded Phase II clinical trial, was conducted according to guidelines of the International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH). The ICH is a cooperative group comprised of regulatory authorities and pharmaceutical industry of Europe, Japan and the United States that discusses scientific and technical aspects of drug registration.
It was performed at the National Medical Research Center (NMRC) in Astana, Kazakhstan’s premier medical research institute, internationally known for initial assessment and treatment of returning National Aeronautics and Space Administration astronauts.
Based upon the outcome of this trial, NMRC is planning a Phase III trial using Stemedica’s itMSCs on a larger patient population — even as parallel Phase II clinical trials in the U.S. and Switzerland are being planned by Stemedica. The U.S.-based trial will take place under Stemedica’s existing Investigational New Drug (IND) Application for the itMSCs with the U.S. Food and Drug Administration. Meanwhile, Swissmedic — Switzerland’s surveillance authority for medicines and medical devices — has found Stemedica’s itMSCs acceptable for clinical trials from Phase I to Phase III.