Raising "good" cholesterol may be more important than lowering "bad" cholesterol to reduce the risk of heart disease, new research suggests.

About 45 per cent of Canadian women and 48 per cent of Canadian men have cholesterol levels that are unhealthy. "Bad" cholesterol, known as LDL or low-density lipoprotein, gets deposited in the walls of artery, leading to heart attacks and strokes.

Joan Esakin, 66, is eating healthier since she had a heart attack two years ago. Her father died early of heart disease.
(CBC)

Drugs known as statins are now among the top-selling medications, lowering LDL levels dramatically. But now, researchers are looking for new ways to help people with cholesterol problems.

"We can cut your chance of having another heart attack by using statins [to] between one third and one half," said Dr. Scott Grundy from Dallas, whose team brought the first statin to market nearly 20 years ago.

"Now that leaves half the risk untouched, and probably statins are not going to touch that, so we have to have new approaches," added Grundy.

Some 60 per cent of high-risk patients who lower their LDL levels will still get heart disease. Some research suggests it's because their good cholesterol levels, called HDL or high-density lipoprotein, are too low.

Lifestyle changes may be part of the picture

HDL acts like a vacuum, sucking out LDL from arteries and taking it back to the liver. If medical researchers can tinker with both HDL and LDL cholesterol levels, they may have a potent, one-two punch against heart disease.

Regular exercise and quitting smoking help raise HDL, but finding drugs that do it safely has proven difficult.

Niacin, or vitamin B3, works to raise HDL significantly when taken in large amounts, but it also carries side effects such as liver damage and intense itching and flushing, said Dr. Jacques Genest, a researcher at Montreal's McGill University.

"I could stand outside in the winter time in just shoes, and I would melt the snow on the ground around me," recalled Joan Esakin of Swan Hills, Alta., who was taking niacin to raise her HDL after she had a heart attack at age 48.

Genest is part of an international trial that is testing whether using the new experimental pill that raises HDL translates into fewer heart attacks and strokes.

"If we use drugs and then neglect lifestyle, especially starting early in life, we will still pay a very high price in terms of heart disease," Grundy said.

For older people with blockages in their arteries or veins who may not benefit much from lifestyle changes, the potential new treatments could add years to their lives by stopping and effectively reversing cardiovascular disease, he added. 

The experimental drug is being developed by Pfizer, the company that now holds the patent on the best-selling statin, Lipitor. The patent is due to expire in 2010, however, and the company hopes to seek regulatory approval for its new HDL in the next two years, aiming to replace one blockbuster drug with another.