London: Scientists have found that infusion of heart`s own stem cells can repair the damage caused to the organ following an attack, a discovery they say could lead to
new treatment strategy for cardiac regeneration.
The study, published in The Lancet, showed that the cells help the organ re-grow healthy muscle after a heart attack, challenging the belief that cardiac scarring is permanent and
that once lost, healthy heart muscle cannot be restored.
In the research, a team led by Prof Eduardo Marban at the Cedars-Sinai Heart Institute in Los Angeles assessed a group of 25 patients, with an average age of 53 years, each of whom had suffered a heart attack.
Patients were treated at the Cedars-Sinai Heart Institute and at Johns Hopkins Hospital in Baltimore. Of these, eight were received standard care while 17 received infusions of
cardiosphere-derived stem cells (CDCs) that were created using the patient`s own heart tissue.
The procedure was less invasive and involved removing pieces of living heart muscle around half the size of a raisin using a catheter under local anaesthetic; this tissue was then used to create the supply of cardiac stem cells.
Each patient then received an infusion of around 12 to 25 million of his or her own stem cells during a second minimally invasive procedure.
Patients who had the stem cell infusion saw their scar size drop from 24 per cent to 12 per cent of the heart on average, while controls saw no reduction in scar size.
"This discovery challenges the conventional wisdom that, once established, cardiac scarring is permanent and that, once lost, healthy heart muscle cannot be restored," said the researchers.
"We show intracoronary infusion of autologous CDCs after myocardial infarction is safe, warranting the expansion of such therapy to phase two study," they added.
The scientists also said that the unprecedented increases they noted "in viable heart muscle, which are consistent with therapeutic regeneration, merit further assessment of clinical outcomes".
Changes in end-diastolic volume, end-systolic volume, and left-ventricular ejection fraction did not also differ between groups by six months, they pointed out.
Only four patients (24 per cent) in the stem cell group had serious adverse events compared with one control (13 per cent), although of the four events in the stem cell group, only one was regarded as possibly related to the treatment.
In a linked comment, Dr Chung-Wah Siu and Prof Hung-Fat Tse of University of Hong Kong said: "These findings suggest that this therapeutic approach is feasible and has the
potential to provide a treatment strategy for cardiac regeneration after myocardial infarction."