Heart disease patients yesterday told how a Hong Kong breakthrough in stem-cell transplants has transformed their lives. In the first human trial of the technique, University of Hong Kong doctors took stem cells from patients' own bone marrow and injected them into their damaged heart muscles or blocked blood vessels. The stem cells - master cells from which the body develops the specialised cells it needs - formed new muscle and vessels, the researchers say. One of the nine who received the treatment at Queen Mary Hospital is Lin Yuen Hsueh, 72. He said: 'Before, I suffered severe chest pains and shortness of breath if I walked a short distance. Now I can walk up to three kilometres in an hour.' The treatment is being hailed as a breakthrough for coronary artery disease patients who do not respond to conventional surgery. The Hong Kong team led by Tse Hung-fat reported the success in this week's issue of British medical journal the Lancet. Of nine patients who received the transplants, seven saw improved heart function. Improvement came after just three months. Kwong Yok-lam, of the university's division of haematology, said: 'There are not too many complications because the stem cells are derived from [the] patient's own bone marrow. There is no [tissue] rejection and no inflammation.' Lau Chu-pak, of the Department of Medicine, said a bigger trial of the treatment, in which some patients would receive only a placebo, was being designed.