Scientists yesterday suggested that they could within a few years help cardiac patients repair and regenerate their hearts by using stem or parent cells from their own organs.
They think they have developed a way of harvesting cells from sick patients and then multiplying them in laboratories into sufficient numbers for treatment.
The cell collection technique, involving probes being sent through a vein in the neck to the right ventricle of the heart, has already been used on 23 patients undergoing treatment for heart failure, an American conference was told.
Tests using pig heart stem cells and tissue have suggested scientists could develop from these clusters, called cardiospheres, new cells that are able to generate electricity and contract, key properties of healthy tissue and essential for any future tackling of heart failure.
In Europe, there has already been some success in transplanting adult bone marrow cells into heart patients, but scientists behind the latest project believe the heart-to-heart transfer offer better prospects for replicating the heart's actions.
Trials involving injecting the newly cultivated cells back into patients' heart tissue may start in about 18 months.
Researchers at Johns Hopkins University's school of medicine and heart institute in Baltimore worked with Rome University scientists to develop the Italian team's initial work in this area, and revealed progress to the American Heart Association's meeting in New Orleans.
If further trials are successful, the technique might reduce the need for heart transplants and eliminate the risk of rejecting donor tissues.
The latest news indicates continuing optimism about the prospects for stem cells, despite the Bush administration's opposition to the use of embryonic cells. Such therapeutic cloning is seen as important for treating spinal cord injuries. But even in the US, much work is going on privately. The harvesting of stem cells, particularly from bone marrow, in living children and adults, and even from umbilical cords, is ethically less of a problem but there have been question marks over their versatility. Nevertheless high hopes have been expressed for their treatment of heart and liver diseases.
Eduardo Marbán, lead investigator of the study, said: "Harnessing the potential benefits of therapy with adult stem cells is imperative if we are to make rapid progress in treating heart disease. Cardiac stem cells grown from the heart itself offer particular promise in that they can regenerate beating heart muscle. Our basic research is trying to overcome the biological problems in harnessing heart stem cells, so we are very excited about our success in growing and analysing these cells."
Studies in pigs have suggested the right ventricle of the heart offers the most abundant source for stem cells. The Johns Hopkins team has removed small samples, 15mg or less, from patients, during 20 minute procedures, and then grown cells from these samples to reproduce them in sufficient quantity, more than 100m cells, the amount thought suitable for therapy. Prof Marbán said: "Our biopsy method was very effective, and within four weeks, most of the sample tissue produced enough stem cells for more advanced clinical testing. Our next step is to test in animals whether these cells can survive and work properly in cases of heart attack and heart failure, using varying dose levels, while also monitoring the electrophysiology in a living heart."
He told the Guardian: "There is nothing we have identified that makes this a remote theoretical treatment."
