Hope & cloud

New Delhi, Sept. 20: In a long-awaited, cautious presentation, a top Indian surgeon today said patients with damaged hearts had improved after being treated with cells taken from their bone marrow. But scientists and doctors have questioned the design of his studies.

Thirty-five patients who had suffered heart attacks and 17 patients with heart failure have received stem cells isolated from their own bone marrow at the All India Institute of Medical Sciences (AIIMS), New Delhi, over the past two years, institute director P. Venugopal said.

The bone marrow is a potential source of stem cells ? identity-less cells that have the unique ability to turn into different cell types. The assumption in these studies is that stem cells, when injected into the heart, will turn into heart muscle cells, thus repairing the damage.

Delivering a talk at an international conference on stem cells in Mumbai today, Dr Venugopal said the studies have indicated “the potential safety” of the use of bone marrow stem cells in patients.

Dr Venugopal ? who had performed India’s first heart transplant in 1994 ? said some of these patients have shown “clinical improvement”.

Conference delegates said neither the exact identity of the cells that the AIIMS doctors have implanted into their patients’ hearts nor the mechanism of their action is clear. Given the study design, it is “hard to attribute the results to the effect of the cells”, said Dr Mahendra Rao from the US National Institutes of Health.

In both sets of patients, the AIIMS doctors used the stem cells as additional therapy to conventional treatment. The heart attack patients received coronary artery bypass grafts while patients with heart failure received the standard drug therapy for heart failure.

Eight of the 17 heart failure patients who received stem cells between February and August this year showed improved heart functions, Dr Venugopal said. There was no improvement in 20 patients who did not receive stem cells.

The patients who received bypass operations and stem cells have also shown improvement, he said. The doctors injected stem cells at the sites of the scars on heart muscle caused by the heart attacks. In patients with heart failure, doctors injected stem cells into arteries.

“The results appear promising, but such studies should ideally be done in a blinded manner,” said Dr Upendra Kaul, a senior cardiologist in Delhi. “The results should be analysed by an independent research team that has nothing to do with delivering the therapy.”