Adult Stem Cells Help Cardiac Function in Angina Patients

(Yale School of Medicine/Wikimedia Commons)

A clinical trial by researchers at Baxter International in Deerfield, Illinois and Northwestern University medical school in Chicago found injections of individuals’ own stem cells reduced angina episodes and improved exercise tolerance time in patients with chronic, severe angina who did not respond to other treatments. The results of the research appear online in the journal Circulation Research.

The phase 2, prospective, double-blind, randomized, controlled clinical trial was conducted at 26 centers in the United States, and tested a patient’s own stem cells of a type known as CD34+. The trial involved delivery of patients’ CD34+ stem cells directly into targeted sites in the heart, with the goal of reducing the frequency of episodes in patients suffering from chronic severe non-responsive angina.

Angina is chest pain or discomfort that occurs when an area of your heart muscle doesn’t get enough oxygen-rich blood, and usually a symptom of coronary heart disease, also called coronary artery disease. Nearly 7 million people in the United States are believed to suffer from angina. Preclinical research suggests CD34+ stem cells may be involved in the creation of new blood vessels and help increase blood flow to tissues.

The researchers extracted stem cells from all participants before randomly assigning them to one of three treatment groups: low-dose or high-dose cell concentrations, or placebo. The team then administered the regimens in 10 distinct sites in the heart tissue using a multi-point injection catheter.

After six months, patients in the low-dose treatment group reported significantly fewer episodes of angina than patients in the control group — 6.8 vs. 10.9 episodes per week — and had fewer episodes at one year after treatment: 6.3 vs. 11 episodes per week. The low-dose treatment group was also able to exercise on a treadmill significantly longer at six months after treatment, as compared with those in the control group: 139 seconds vs. 69 seconds, on average.  Angina episodes and exercise tolerance rates were also improved in the high-dose treated group at six months and at one year post treatment compared to the control group.

Three deaths occurred during the trial — all in the control group — one from procedural complications of cardiac surgery, the others unrelated to the treatment. Heart attacks (myocardial infarction) occurred in seven of the control group patients. There were three heart attacks each in the low-dose and high-dose patient groups.

Read more: Early Trial Indicates Stem Cells Can Reverse Heart Damage

*     *     *