Genetics may Play Role in Heart Health

More people in the Western world die of heart disease than of any other cause, led by heart attacks and strokes that, in America

More people in the Western world die of heart disease than of any other cause, led by heart attacks and strokes that, in America, together kill roughly 900,000 people a year.

Another 70 million Americans live with heart disease, says Benjamin D. Horne, director of cardiovascular and genetic epidemiology at LDS Hospital.

Today, Horne and John A. Carlquist, co-director of LDS Hospital cardiovascular research, will take phoned-in questions about genetics and heart disease from 10 a.m. to noon during the Deseret Morning News/Intermountain Health Hotline.

Horne notes that while most heart attacks and strokes strike people 65 and older, the number in younger patients has increased. And each year, more than 6 million people are hospitalized in America because of cardiovascular disease. The financial cost is estimated at about $403 billion, including medical expenses and lost work.

LDS Hospital researchers hope to unravel some of the mysteries of heart attack and early-onset coronary-artery disease, which means before 55 in males and 65 in women. For conditions like aortic valve disease or mitral valve disease, onset before age 50 is considered early.

They're building on studies that have identified a few genetic variations related to early-onset disease. "There is quite a plethora of candidate genes that have been looked at over a couple of decades in terms of predicting onset of heart attack," Horne says.

It's a complicated process and often an initial finding of a gene associated with heart attack or coronary disease has been hard to replicate. There are exceptions. In a couple of diseases, variants associated with the higher risk of heart attack have been identified. Most, though, have not.

The Utah researchers are taking a couple of approaches. They're looking at people who are unrelated to each other but share a history of early-onset heart attack, comparing their genetic markers to another group who are very old and have never had heart disease.

They hope to find what the two groups do not have in common, genetically, by testing more than a half-million genetic variations across the entire genome. "It's a fishing expedition, and we don't know what we're going to find," Horne says.

They're also looking at heart-disease clusters in families, using the Utah Population Database.

Patients in the cath lab at LDS and McKay-Dee hospitals are being asked for blood samples. If they find someone with a strong family history or early-onset disease, Horne says they approach the more extended family to invite them into a study.

While Horne says most people know that heart attacks tend to cluster in families, many don't realize that mitral-valve or aortic-valve disease may be genetic, as well. LDS Hospital first found familial clusters of aortic-valve disease, a study validated by follow-up research in southwest France.

Some doctors tell patients with valve problems there's no genetic basis. It's not necessarily true. And there appear to be links between some parents' and children's defects, even if they are different defects.

"There's quite a bit we don't know," says Horne, who believes Congress was "a bit oversold" on how soon results would come once the human genome was plotted. It takes time and careful research, but Horne, Carlquist and other experts believe the research will one day lead to treatments that give patients specific drugs or devices that will work for them.

Genetics can be used to find new drug targets, as well. It might one day translate to meaningful prevention, Horne says.

"If we could substantiate what genetic markers have an effect on disease, we might be able to tap someone in childhood or infancy and predict risks for the future, help parents understand how to tailor their lifestyle to prevent those effects," he says.

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