The minimally-invasive procedure was completed on the first patient on June 26, as part of a Phase I investigative study approved by the U.S. Food and Drug Administration and supported by the Specialized Centers for Cell-based Therapies at the National Heart, Lung, and Blood Institute and the Donald W. Reynolds Foundation.
"This procedure signals a new and exciting era in the understanding and treatment of heart disease," said Dr. Eduardo Marban, director of the Cedars-Sinai Heart Institute, who developed the technique and is leading the clinical trial.
"Five years ago, we didn't even know the heart had its own distinct type of stem cells. Now we are exploring how to harness such stem cells to help patients heal their own damaged hearts," Dr. Marban added.
Kenneth Milles, a 39-year-old controller for a small construction company in the San Fernando Valley, is the first patient on whom this procedure has been completed. He had experienced a heart attack on May 10 due to a 99 percent blockage in the left anterior descending artery, a major artery of the heart.
The patients will be monitored for six months, and complete results are scheduled to be available in late-2010.
There are 24 patients participating in the study, being conducted in collaboration with researchers from the Johns Hopkins University, where Dr. Marban worked prior to joining Cedars-Sinai in 2007.
All of them have hearts that were damaged and scarred by heart attacks. Once enrolled in the study, patients go through a three-step procedure.
The doctors first conduct extensive imaging to pinpoint the exact location and severity of the scars wrought by the heart attack, and then the patient undergoes a minimally-invasive biopsy, with local anaesthesia.
Using a catheter inserted through a vein in the patient's neck, doctors remove a small piece of heart tissue, about half the size of a raisin. The heart tissue is then taken to a specialized lab at Cedars-Sinai, where heart stem cells are cultured using methods invented by Marban's team.
Marban has revealed that it takes about four weeks for the cells to multiply to numbers sufficient for therapeutic use, approximately 10 to 25 million.
According to the researcher, the final step involves the re-introduction of the multiplied stem cells into the patient's coronary arteries during a second catheter procedure.
Marban points out that unlike bone marrow cells, heart stem cells are naturally programmed to regrow heart tissue, so they could prove more effective in healing the injury caused by heart attacks.
"If successful, we hope the procedure could be widely available in a few years and could be more broadly applied to cardiac patients," says the researcher.