Two small studies of cardiac stem cells for the treatment of heart failure have shown promise, but ABC News, CBS News and other media outlets are throwing around words like “medical breakthrough” and “heart failure cure.” ABC News correspondent Richard Besser was so enthusiastic that anchor Diane Sawyer commented that she had never seen him “so excited.” The first author of one of the studies, Roberto Bolli, said the work could represent “the biggest advance in cardiology in my lifetime.”
The reality may be somewhat more prosaic. In the first paper, published in the Lancet, Roberto Bolli and colleagues, including senior author Pierro Anversa, report on a phase 1 study still in progress in which 16 patients with post-infarction left ventricular (LV) dysfunction received cardiac stem cells (CSCs) harvested during bypass surgery and subsequently expanded. Seven patients served as controls.
In the treatment group LV ejection fraction (EF) increased from 30.3% to 38.5% 4 months after infusion. There was no change in the EF in the control group. At one year followup in 8 patients in the CSC group the LVEF had increased by 12.3 EF units.
“Although the primary purpose of our phase 1 trial was to assess the safety and feasibility of using this distinct and unique population of cells, the treatment effects are very encouraging and compare favorably with previous trials of bone marrow cells. The present results provide a strong rationale for further studies of CSC treatment in patients with severe heart failure secondary to ischemic cardiomyopathy, who have a poor prognosis,” the authors wrote.
The results “raise new optimism because the study is based on rigorous quality standards and the reported benefits are of an unexpected magnitude,” writes Gerd Heusch in an accompanying comment. ”Of course,we will have to see whether further data will meet the promises of the present study…”
In a second study, presented by Eduardo Marbán at the AHA, 31 patients were randomized on a 2:1 basis to intracoronary infusion of CDCs or a control arm. CDC therapy was safe, and the investigators found evidence that it reduced scar and increased healthy heart muscle. The results suggested that regeneration of cardiac tissue had taken place. Positive trends suggesting improved EF and end systolic and diastolic volumes were also observed. The results, the authors concluded, suggest that this could be the “first therapeutic modality to shrink scar while regrowing viable, functional tissue.”
Here is the press release from the Lancet: the
First-in-man study shows cardiac stems cells show promise for treatment of heart failure caused by ischaemic heart disease (The Lancet)
The first trial in humans to use the heart’s own stem cells to battle heart failure has produced promising results. The initial findings from this ongoing study appear in an Article published Online First in The Lancet, timed to coincide with a presentation at the American Heart Association’s Scientific Sessions meeting, Orlando, FL, USA. The Article is by Professor Roberto Bolli, University of Louisville, KY, USA and Professor Piero Anversa, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA, and colleagues.
Heart failure is a common, lethal, disabling, and expensive disorder. The most common cause of heart failure in the developed world is ischaemic heart disease—a blocking of the heart blood vessels causing death of heart muscle tissue. This leads to the heart pumping less blood, resulting in a decrease in left ventricular ejection fraction (LVEF). Available treatments do not address the fundamental problem of the loss of cardiac tissue.
The adult heart contains cardiac stem cells (CSCs) that are self-renewing, clonogenic (able to produce identical daughter cells), and multipotent—ie, they differentiate into all three major cardiac lineages (myocytes, vascular smooth muscle cells, and endothelial cells). In animal models, CSCs have helped improve heart failure, but these cells have never been tried in humans. In this study, the authorsdid a phase 1 clinical trial of CSCs in patients with heart failure after a heart attack to assess the safety and feasibility of intracoronary CSC infusion, and to test the hypothesis that this intervention would improve the contractile function of the heart and the general clinical status of the patient.
The authors report the results in 23 patients with severe heart failure (LVEF <40%), each of whom has had coronary artery bypass grafting (CABG). 16 of these received CSCs, while the other seven (control group) received standard care. Patients received an infusion of 1 million CSCs via a balloon catheter, at a mean time of 4 months after their CABG. In 14 CSC-treated patients who were analysed, LVEF increased from 30·3% before CSC infusion to 38·5% at 4 months after infusion. LVEF did not change in the control group. Importantly, the positive effects of CSCs were even more pronounced at 1 year in eight of the CSC patients, in whom LVEF increased by 12.3% (from 30.2% before CSCs to 42.5% at 1 year). In the seven treated patients in whom cardiac MRI could be done, the size of the dead tissue (infarct) decreased from 32·6 g by 7·8 g (24%) at 4 months and 9·8 g (30%) at 1 year.
The authors conclude: “Our study is the first report of the administration of CSCs in people. The results are a significant addition to the current data because they introduce a new potential treatment for heart failure… The present results provide a strong rationale for further studies of CSC treatment in patients with severe heart failure secondary to ischaemic cardiomyopathy, who have a poor prognosis.”
In a linked Comment, Professor Gerd Heusch, University School of Medicine, Essen, Germany, says: “The results from SCIPIO raise new optimism because the study is based on rigorous quality standards and the reported benefits are of an unexpected magnitude…we will have to see whether further data will meet the promises of the present study: more patients will need to be followed up over a longer period.”
He concludes: “It is to be hoped that SCIPIO has the same potential to transform cardiac cell therapy that its namesake Scipio Africanus achieved in Roman military campaigns against Karthago.”