Heart failure is a common, disabling, deadly and costly disorder. Ischemic heart disease is the most widespread cause of heart failure in the developed world. In ischemic heart disease, the heart's blood vessels are blocked causing the heart muscle tissue to die, causing less blood to be pumped through the heart, which subsequently results in a decrease in left ventricular ejection fraction (LVEF). So far, no treatment is available for the loss of cardiac tissue.
Cardiac stem cells (CSCs) in adult hearts are self-renewing, clonogenic, meaning they are able to produce identical daughter cells. CSCs are also multipotent, differentiating into all three major cardiac lineages, such as endothelial cells, vascular smooth muscle cells, and myocytes.
Animal models have demonstrated that CSCs have assisted in improving heart failure, however, this has never been tried in humans.
Professor Roberto Bolli and Professor Piero Anversa and their team conducted a phase 1 clinical trial of CSCs in patients with heart failure following a heart attack in order to evaluate the safety and feasibility of intracoronary CSC infusion. They also decided to examine the hypothesis of whether this intervention would improve patients' heart's contractile function and the general clinical status of the patients. For the trial, the researchers evaluated 23 patients with severe heart failure (LVEF <40%), who had all received coronary artery bypass grafting (CABG). The patients were randomized with 16 patients receiving CSCs, while the other seven, the control group, received standard care. At a mean time of 4 months following their CABG, patients in the CSC group were administered with an infusion of 1 million CSCs via a balloon catheter.
The researchers discovered that LVEF increased from 30.3% in 14 patients before their CSC infusion to 38.5% at 4 months afterwards in the CSC group, whilst in the control group LVEF remained unchanged.
Significantly, the researchers noted at 1 year that in 8 patients of the CSC group, the positive effects of CSCs were even more distinct, observing a 12.3% increase in these patient's LVEF from 30.2% before CSCs to 42.5%. They also reported that at 4 months, seven treated patients who were able to receive a cardiac MRI, showed a 7.8 g decrease in dead tissue (infarct) from 32.6 g (24%) and 9.8 g (30%) at 1 year.
In a concluding statement the researchers say:
"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 ischemic cardiomyopathy, who have a poor prognosis."
Professor Gerd Heusch at the University School of Medicine in Essen, Germany, supports the study in a linked comment, saying:
"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. 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."