Family History Has Strong Effect on Cardiac Risk
By Ed Edelson
HealthDay Reporter on 09/07/2007
FRIDAY, Sept. 7 (HealthDay News) -- Paying attention to the heart risk factors of close relatives of people with coronary heart disease could prevent more than 40 percent of early heart deaths, Scottish researchers say.
"If you want primary prevention, you have to go through the population to find groups with high risk," explained Dr. Jill Pell, professor of epidemiology at the University of Glasgow and lead author of a report in the Sept. 8 issue of the British Medical Journal.
"The 14 percent of families that have a history of coronary heart disease account for 72 percent of all premature deaths from heart disease," Pell pointed out.
That number comes from previous studies, which showed that 48 percent of major coronary events such as heart attacks occur in those families, Pell added. A brother or sister of someone who has a heart attack or other coronary event has twice the normal risk of having such an event, she said.
"So, instead of going through the entire population [for screening], we can go through the closest relatives of coronary disease patients," she reasoned.
Screening those close relatives and taking steps against risk factors such as high cholesterol, smoking, diabetes and high blood pressure could prevent more than 80 percent of the early heart attacks that occur in Britain each year, the Glasgow group estimated.
They plan to put that belief to a practical test with a pilot project to screen siblings and children of coronary heart disease patients, select those with obvious risk factors, and then work to bring those factors under control, Pell said.
"We would aim at global risk, all the factors together -- smoking, cholesterol, diet, exercise," she said.
In theory, working physicians are aware of the importance of family history in predicting coronary risk, Pell said. And they know that they should put that information to use with the close relatives of heart patients.
However, "the reality is that all of the studies to date show that it just isn't happening," she said.
People with coronary heart disease often show up in emergency rooms or outpatient clinics, the researchers noted. It would be easy to flag them as members of a family requiring counseling. In fact, such a flagging system is used for cancers that are known to have an inheritable background, the report's authors noted.
It would be easy to ask a heart patient if any close relatives have such a condition, Pell said, and to give basic advice when that is the case: "Tell your brother to check out his risk factors and modify them if necessary."
In the United States, the Sibling Family Heart Study, which has followed more than 800 people for more than a decade, has seen "a doubling of the number of heart attacks, deaths and events that need to be corrected with bypass surgery or angioplasty," added Dr. Dhananjay Vaidya, assistant professor of internal medicine at the Johns Hopkins University, Baltimore, and a member of that study team.
"One surprising thing we found was that people who had early heart attacks and had a family history of heart disease had very little knowledge of how they were at greater risk," Vaidya said.
After all other risk factors are taken into account, having a close family member with coronary heart disease increased a person's risk of a major cardiac event by 45 percent, he said.