63-year-old Larry McDonald has had two major heart attacks. Now he's enrolled in the Aim-High study hoping to prevent another one.

"With this study, we're supposed to lower the bad cholesterol and raise the good and hopefully that's gonna happen," McDonald said.

Participants in the nationwide study will receive Simvastatin to lower LDL or bad cholesterol.

"Somewhere down to below 100, perhaps below 80," cardiologist Dr. Michael Miller. "And then half of them will, in addition to a statin, will be placed on a medication to raise the good cholesterol or HDL."

That medication is Niaspan, a prescription-strength, long-lasting niacin, a B-3 vitamin proven to raise good cholesterol.

"With low doses it is, it's viewed as a vitamin, but at higher doses, such as about 50 milligrams a day, we would view it as more of a medicinal agent," Miller said.

The study is the first to compare the effects of a niacin-statin combination to a statin alone.

"The hypothesis is that raising the levels of the good cholesterol, lowering the blood fats, above and beyond just lowering bad cholesterol will add additional benefit," Miller said.

Dr. Miller says positive findings from the study could change the way doctors care for people with heart disease.

"In the big picture, we would hope that attending to all the good and bad cholesterols would make a difference," Miller said.

It is a difference that could prevent heart attacks and save more lives.

Researchers are still enrolling participants for the study. For more information, log onto Aim-High. The study is funded by the National Heart, Lung and Blood Institute and Kos Pharmaceuticals, the maker of Niaspan.