Ignored cholesterol blamed for heart attacks

By Michael Kahn

LONDON (Reuters) - Danish researchers said on Tuesday they have found the strongest evidence yet that an often ignored form of cholesterol can cause heart attacks.

They said people with higher levels of a little-understood form of cholesterol called lipoprotein (a), which varies up to a thousand fold from one person to another, were also more likely to have heart attacks.

Statins -- taken by millions to cut heart attack and stroke risk -- do not affect lipoprotein (a) but the findings may encourage the development of new cholesterol-lowering drugs, said Borge Nordestgaard of Copenhagen University Hospital, who led the study.

The research, published in the Journal of the American Medical Association, showed that people with the highest liporotein (a) levels were two to three times more likely to have a heart attack than those with the lowest levels.

"We have shown that lipoprotein (a) is causing heart attacks," Nordestgaard said in a telephone interview.

Lipoprotein (a) is one of several forms of cholesterol found in the blood, with levels determined almost entirely by genetics.

Statins lower levels of low-density lipoprotein, commonly known as "bad" cholesterol. Top-selling statins include Pfizer's Lipitor, known chemically as atorvastatin, and AstraZeneca's Crestor, or rosuvastatin.

"This study may explain why statins don't work for some people," Nordestgaard said.