Stem-cell infusions suggest treatment for heart failure

THE FIRST trial to use the heart's own stem cells to treat heart failure in humans has produced promising results, according to research published yesterday in the Lancetmedical journal.

The findings, which were simultaneously presented at the annual scientific conference of the American Heart Association in Orlando, Florida, show that patients with severe heart failure regained function in their heart muscle leading to an improvement in their condition after they were treated with cardiac stem cells.

Adult hearts contain stem cells that are self-renewing; they have the ability to turn into heart muscle or heart vessel cells. The researchers, from the University of Louisville, Kentucky and Harvard Medical School, Boston, are the first to infuse cardiac stem cells into humans suffering from heart failure after a heart attack.

The most common cause of heart failure in the developed world is coronary heart disease where the blockage in the heart’s own blood vessels causes heart muscle tissue to die. As a result, the pumping ability of the heart is reduced so that less blood reaches vital organs. The main symptoms of heart failure are breathlessness on exercise and swelling in the legs as blood pools in different parts of the body. The prognosis for heart failure is poor with a mortality of almost 50 per cent some five years after diagnosis.

Prof Roberto Bolli and his colleagues infused the stem cells, which had been harvested four months earlier from each patient’s heart during a coronary artery bypass operation, directly into the hearts of some 16 patients. All had severe heart failure and had been shown to have less than 40 per cent of normal pumping strength in their hearts. Another seven matched participants acted as a control group. In 14 of the treated patients, the measure of pump strength increased from 30 to 39 per cent some four months after cardiac stem cells were infused.

The positive effects were even more marked one year after treatment in eight patients who demonstrated a 12 per cent improvement. There was no change in pump strength in the control group.

These are preliminary results from the trial which is ongoing. The authors said “our study is the first report of the administration of cardiac stem cells in people. The results are a significant addition to the current data because they introduce a new potential treatment for heart failure.”

The report concludes, “The present results provide a strong rationale for further studies of cardiac stem cell treatment in patients with severe heart failure secondary to ischaemic cardiomyopathy (heart muscle damage due to coronary heart disease), who have a poor prognosis.”

In a linked commentary in the Lancet, Prof Gerd Heusch, of the University School of Medicine, Essen, Germany, said: "The results 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."