Medical DevicesHeart Attack Patient Treated With Own Heart Stem Cells In Clinical Trial
Doctors at a heart center in the US announced yesterday that the first of 24 heart attack patients taking part in a clinical trial has successfully
undergone a procedure where his own heart tissue was used to grow specialized heart stem cells that were then injected back into his heart where it is
hoped they will repair and regenerate healthy heart muscle in place of that injured by heart attack.
Doctors at the Cedars-Sinai Heart Institute in Los Angeles said that the minimally-invasive procedure was completed on the first patient, Kenneth
Milles, last Friday. Milles, who is 39, works as a controller with a small construction company in San Fernando Valley.
The operation is part of a phase I investigative trial approved by the US Food and Drug Administration (FDA) and funded by the Specialized Centers
for Cell-based Therapies at the National Heart, Lung, and Blood Institute and the Donald W Reynolds Foundation, they announced.
Dr Eduardo Marban, director of the Cedars-Sinai Heart Institute, developed the technique and leads the trial. He told the media that:
"This procedure signals a new and exciting era in the understanding and treatment of heart disease."
"Five years ago, we didn"t even know the heart had its own distinct type of stem cells," said Marban.
"Now we are exploring how to harness such stem cells to help patients heal their own damaged hearts," he added.
Marban also holds the Mark Siegel Family Foundation Chair at the Cedars-Sinai Heart Institute and directs Cedars-Sinai"s Board of Governors Heart
Stem Cell Center.
The Cedars-Sinai team are working on the trial with other colleagues at Johns Hopkins University, where Marban was based before joining Cedars-
Sinai in 2007 and where he developed the new heart stem cell method used in this trial.
For the study, Marban and colleagues will be enrolling a total of 24 patients whose hearts have been damaged and scarred by heart attacks.
A heart attack is when blood can"t flow to heart muscle, usually because an artery is blocked. The tissue becomes scarred (ie some of it dies off)
because of lack of oxygen.
A requirement of enrollment is that all patients must have had a heart attack within the last four weeks. In this first stage of the trial, four patients will
receive 12.5 million stem cells and two patients will act as controls.
In a few months time another 12 patients will receive 25 million stem cells and 6 will act as controls.
Each patient who is to receive stem cells goes through a three step procedure: location and removal of heart tissue, culturing of stem cells, and re-insertion of stem cells.
To locate the heart tissue the doctors perform extensive imaging to find the exact sites in the heart that have been damaged and scarred by heart attack.
Then they perform a minimally invasive biopsy, under local anesthetic, and remove a small piece of heart tissue, about half the size of a raisin. This is
done through a catheter inserted in a vein in the patient"s neck.
In the second step, the doctors take the heart tissue and use it to grow heart stem cells using in a
specialized lab at Cedars-Sinai. After about 4 weeks the culture contains some 10 to 25 million stem cells.
The third step is where the doctors put the stem cells back into the patient"s coronary arteries, again using a catheter.
The first patient, Milles, had a heart attack on 10 May, which was caused by a 99 per cent blockage in a major heart artery (the left anterior descending
artery). Extensive imaging showed that 21 per cent of Milles" heart muscle was scarred by the attack. He had a biopsy on 24 May and received his
infusion of stem cells on 29 June.
Milles will be kept under observation for 6 months. Marban and colleagues said they hope to release the final results sometime toward the end of
2010.
Marban said the cardiac stem cell method is a logical development of the bone marrow one, where recent studies show that over 500 cardiac patients
have experienced some improvement after being treated with bone marrow stem cells.
However, bone marrow stem cells are not ideal for cardiac repair because they are not naturally programmed to generate heart muscle, so when cardiac
stem cells were discovered 5 years ago, Marban and colleagues starting working on a method that used these instead of bone marrow stem
cells.
It the trial is successful, Marban and his team hope the procedure can be available in a few years time, and "could be more broadly applied to cardiac
patients". They also see the benefit in terms of cost, because every heart damaged patient successfully treated via stem cell therapy is one less patient
undergoing expensive and high risk treatment such as a heart transplant.
Heart attack is a leading killer of men and women in the US where 1.5 million attacks occur each year with 500,000 deaths.
The most common cause of heart attack is coronary artery disease where fatty plaque builds up over many years on the inner walls of the arteries that
take blood and oxygen to the heart. Eventually this build up can rupture and cause a clot which can partially or completely stop the blood flow and
starve the tissue of oxygen.
PR Newswire, NHLBI, Women"s Heart Foundation.
Written by: Catharine Paddock, PhD
Copyright: Medical News Today
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