A study published Online First by The Lancet shows that infusion of cardiac stem cells into patients who had had heart attacks can help regenerate healthy heart muscle. The Article is by Professor Eduardo Marbán, Cedars-Sinai Heart Institute, Los Angeles, CA, USA, and colleagues.
The study assessed 25 patients, average age 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, 8 received standard care while 17 received infusions of cardiosphere-derived stem cells (CDCs: special cardiac stem cells created using the patient's own heart tissue). Each patient underwent extensive imaging in order to pinpoint the exact location and amount of the scar tissue in the heart that had resulted from the heart attack.
The procedure was minimally 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% to 12% of the heart on average (a reduction by about 50%), while controls saw no reduction in scar size. Changes in end-diastolic volume, end-systolic volume, and left-ventricular ejection fraction id not differ between groups by 6 months.
Four patients (24%) in the stem cell group had serious adverse events compared with one control (13%), although of the four events in the stem cell group, only one was regarded as possibly related to the treatment.
The authors say: "This discovery challenges the conventional wisdom that, once established, cardiac scarring is permanent and that, once lost, healthy heart muscle cannot be restored."
They add: "We show intracoronary infusion of autologous CDCs after myocardial infarction is safe, warranting the expansion of such therapy to phase 2 study. The unprecedented increases we noted in viable heart muscle, which are consistent with therapeutic regeneration, merit further assessment of clinical outcomes."
In a linked Comment, Dr Chung-Wah Siu, and Professor Hung-Fat Tse, Cardiology Division, Li Ka Shing Faculty of Medicine, University of Hong Kong, China, say: "These findings suggest that this therapeutic approach is feasible and has the potential to provide a treatment strategy for cardiac regeneration after myocardial infarction."
For Professor Eduardo Marbán, Cedars-Sinai Heart Institute, Los Angeles, CA, USA, please contact Sally Stewart. T) +1 310 248 6566 E) Sally.Stewart@cshs.org
Professor Hung-Fat Tse, Cardiology Division, Li Ka Shing Faculty of Medicine, University of Hong Kong, China. T) +852-2255-3598 E) hftse@hkucc.hku.hk
Journal
The Lancet