Patient's Own Stem Cells May Treat Heart Disease
Preliminary data presented as a late-breaking abstract at the American College of Cardiology's 58th annual scientific session from the largest CD34+ adult stem cell study for heart disease has shown the first evidence that delivering a potent form of autologous (from the patient) adult stem cells into the heart muscle of patients with severe angina may result in less pain and improved exercise tolerance.
Northwestern Memorial Hospital was the lead site for the six-month trial, results of which were presented by principal investigator Douglas Losordo, MD, director of the Feinberg Cardiovascular Research Institute and director of cardiovascular regenerative medicine at Northwestern Memorial.
"The results from this study provide the first evidence that a patient's own stem cells could actually be used as a treatment for their heart disease," said Losordo, who also is the Eileen M. Foell Professor of Heart Research at Northwestern University’s Feinberg School of Medicine. "The study provides potential hope for those patients with currently untreatable angina to be more active with less pain.”
Losordo cautioned that the findings of the 26-site trial, while encouraging, are not yet definitive and require verification in a larger study. The autologous stem cell transplant is the first therapy to produce an improvement in patients with severe angina, measured by their ability to walk on a treadmill. Six months after the procedure, the autologous stem cell transplant patients were able to walk longer (average of 60 seconds) on a treadmill than the placebo group. It also took longer until they experienced angina pain on a treadmill compared to the placebo group and, when they felt pain, it went away faster with rest. In addition, they had a reduction of episodes of chest pain compared to the control group.
Out of the estimated one million people in the U.S. who suffer from chronic, severe angina -- chest pain due to blocked arteries -- about 300,000 cannot be helped by any traditional medical treatment such as angioplasty, bypass surgery or stents. This is called intractable angina, the severity of which is designated by classes. The patients in the study were Canadian Classification System (CCS) class 3 or 4, meaning they had chest pain from normal to minimal activities such as brushing their teeth or even resting.
"Muscle hibernates because it wants to decrease energy consumption to stay alive," Losordo explained. "It's not getting enough oxygenated blood to perform normally, so it shuts down its contractile function."