NZ scientists find heart disease link

New Zealand scientists have uncovered a previously unknown genetic link to heart disease.

Worldwide around 100 genes have been linked to various aspects of heart disease, including the inherited risk of death from a sharp change in heart rhythm. Some of the genes involved occur only in certain ethnic groups.

Cardiovascular disease - which is mainly heart disease and stroke - is the leading cause of death in New Zealand.

Scientists at the Christchurch medical school have found links between a certain gene variation and increased risk of two conditions: type 2 diabetes and oxidative damage in heart failure.

The variation is in the gene ATIR. It modifies how an angiotensin hormone interacts with the heart and blood vessels.

Dr Vicky Cameron, of the school's Cardioendocrine Research Group, presented the findings to the Medical Sciences Congress in Queenstown last week.The group's director, Professor Mark Richards, said oxidative damage from so-called free radicals (unstable atoms linked to cell damage) was thought to be one of the common ways in which tissue was damaged.

"With heart disease you don't want oxidation damage because it increases stress," he said.

Earlier research by the group found that the risk of dying within five years of a heart attack was eight times higher in those patients who had a certain variant of the angiotensin converting enzyme (ACE) gene.

Professor Richards said the future hope was that by identifying individuals' genetic susceptibility to the various risks for heart disease, targeted treatment could be designed for them.

"At the moment we have a one-size-fits-all approach."

The known risk factors that can be modified are smoking, high cholesterol, high blood pressure and lack of exercise; the unchangeable ones are increasing age, being a male, a family history of heart disease and having diabetes.

Currently half the cases of cardiovascular disease cannot be attributed to these factors.