/ 26 April 2004

Stem cell therapy holds out hope to heart patients

Patients suffering from heart failure might be able to ”regrow” muscle and blood vessels in their own failing organs with the help of stem cells transplanted from their hip bones, surgeons said yesterday.

Trials at several centres in South America provided ”the first convincing evidence” that injection of cells could provide viable treatment for the condition, researchers told the American Association for Thoracic Surgery, meeting in Toronto.

The idea is that stem cells, ”parents” for a range of other cells, could turn into heart muscle cells and blood cells, that could improve the heart’s ability to contract more efficiently and thus restore blood supply to the heart.

Twenty patients were enrolled for the trials, involving surgeons from Pittsburgh University, Baylor University medical centre, Dallas, and the Benetti Foundation in Rosario, Argentina.

They all had bypass operations, with pieces of vein grafted round coronary arteries, but half also received stem cells from bone marrow in their hips. These were injected in 25 to 30 sites where there was obvious muscle damage.

Follow-up checks over six months suggested those who received stem cells had better heart function, without side-effects or complications.

A protein marker judged important for communication between cells was also more evident in patients who had received the stem cells.

”We don’t know if this increase was due to the growth of new heart muscle cells resulting from the stem cell injections or whether the stem cells coaxed existing cells to come out of hibernation,” said Amit Patel, of Pittsburgh University’s school of medicine.

”Further investigation is needed to replicate these results, quantify the optimal timing of the injection, and look at the cellular effects of the therapy.”

The South American trials are continuing and in a separate study two patients with inoperable heart failure in Uruguay have received stem cells injected into the heart. A patient in Palermo, Sicily, will soon undergo a similar procedure.

Further research at Pittsburgh is expected to involve injection of stem cells into patients implanted with devices to help keep their hearts beating. Surgeons hope at least one of these might receive a heart transplant, enabling them a rare opportunity to study more closely the effect of the stem cell injections.

Robert Kormos, professor of surgery at Pittsburgh, said: ”These results encourage us aggressively to pursue cellular therapies as an option for congestive heart failure. It will revolutionise our approach, which is largely palliative, to one that is truly regenerative.”

Belinda Linden, head of medical information for the British Heart Foundation, said: ”This small but important study offers yet more evidence of the potential benefits of stem cells when injected into damaged heart tissue. This is particularly significant as incidence of heart failure is increasing.”

But she added: ”It must be remembered this treatment is experimental.” – Guardian Unlimited Â