Scientists at Freiburg University in Germany have succeeded in growing new arteries in the hearts of rats, where none had been before, by implanting a human growth factor which is involved in the natural mechanism of wound-healing.
If the experiment is safe and works in man, it could mean a new era of non-surgical heart treatment. Instead of bypass surgery - in Britain, the commonest form of surgery for heart disease with about 15,000 operations conducted each year - the growth factor could be implanted through a catheter or injected on to the heart.
The scientists described how the laboratory had first identified the growth factor, a type of protein which initiates the growth of new blood vessels necessary for wound-healing. Then they genetically manipulated E coli bacteria to produce this angiogenetic growth factor and implanted it between the aorta, the major arterial vessel leading out of the heart, and the surface of the heart muscle. After nine weeks, they were able to see that new arteries had formed, creating bridges between aorta and the heart muscle.
Dr Roland Fasol, a member of the team, said that despite advances in knowledge and treatment, heart disease remained the big killer. 'The ultimate therapy is still coronary surgery, if conservative and conventional treatment fails. But the surgeon is faced with the problem of limited availability of his patients' own graft material for his operation.'
He said the experiment had proved the feasibility of the technique and further research is under way to test its safety and the permanence of the new blood vessels.
One concern is to make certain that the growth factors which promote rapid growth of cells do not, at the same time, encourage the growth of cancer cells. Kirsten Schlaudraff, head of the Freiburg laboratory, said that so far their angiogenetic growth factor showed no sign of encouraging cancer and it might be possible to try it in human heart patients in about three years time.