The group, sponsored by the federal government, proposes nearly tripling the number of adults who should be taking cholesterol-lowering drugs and raising by 25 percent the number who should be on cholesterol-lowering diets.
``We want to recommend more aggressive treatment to people who are at very high risk,'' said James I. Cleeman, the coordinator of the group that issued the guidelines, the National Cholesterol Education Program of the National Heart, Lung, and Blood Institute.
``And,'' he added, paraphrasing Shakespeare, ``there are more of them out there than are dreamt of in your philosophy.''
The new recommendations increase the number of Americans who are candidates for cholesterol-lowering drugs to about 36 million from 13 million, with the old guidelines. The number who should be on cholesterol-lowering diets is raised to 65 million from the current 52 million.
An executive summary of the report was to be published today in the Journal of the American Medical Association.
Claude Lenfant, the director of the institute, said that if the American public took the new guidelines seriously, heart disease could slip from its ranking as the nation's leading cause of death.
``It would no longer be the No. 1 killer,'' he said.
More than a million Americans have heart attacks each year, and a half-million die from heart disease.
The guidelines are intended to simplify the process by which people determine whether they are at risk for heart disease. The well-known cholesterol levels remain largely the same, but a formula is added to them that clearly estimates the chance that a person may have a heart attack in the next 10 years. It calculates risk for men and women according to age, cholesterol level, smoking status and blood pressure.
The new guidelines continue to recommend an overall cholesterol level of about 200 milligrams per deciliter. But, until Tuesday, 240 mg of LDL, or ``bad'' cholesterol, was considered high. Now 130-159 mg of LDL is borderline high, 160 mg is high and 190 mg is very high.
The authors also toughened recommendations for HDL, or ``good'' cholesterol, which can actually reduce heart disease risk. The ``too low'' level was increased from 35 mg to 40 mg.
The panel urged that people whose risk of heart attack is 20 percent or more be treated as aggressively as patients who have just had heart attacks. That almost always means the immediate use of cholesterol-lowering treatments, most often statins, powerful drugs that can slash cholesterol levels by blocking a liver enzyme crucial to cholesterol production.
People with diabetes are now automatically put into this high- risk category. Previously, diabetes was considered simply another risk factor, rather than a danger sign as glaring as having already had a heart attack.
``The medical community is pretty well attuned to the fact that if you had a heart attack, you are at high risk for having another one,'' Cleeman said. ``But what is not well known is that there are other people who are at just as high risk.''
Valentin Fuster, a cardiologist at the Mount Sinai School of Medicine in New York and a past president of the American Heart Association, emphasized that this aspect of the guidelines was a pronounced change.
``You are targeting a population that has never had a heart attack,'' Fuster said.
Those people used to be handed a diet to start and given more modest goals for cholesterol reduction.
Another change was in how to treat people who have had heart attacks, said Michael Lauer, who directs clinical research in cardiology at the Cleveland Clinic Foundation and is a co-author of an editorial accompanying the guidelines in The Journal of the American Medical Association.
Diet, exercise and weight reduction are the primary recommendations for people only at lower risk - with elevated cholesterol levels but with less than a 20 percent chance of having a heart attack in the next decade.
But even some of those people should take drugs, depending on their cholesterol levels, according to the guidelines. Some with particularly high levels of LDL cholesterol, which injures blood vessel walls, might consider taking a drug.
The last time the national panel issued cholesterol treatment guidelines was in 1993. So much has changed since then, heart disease researchers said, that those much less aggressive guidelines now seem to be of a different era.
``There was this enormous dissent 10 years ago,'' Lauer said. Many medical experts took issue with the idea of aggressively treating patients such as older people or people who had no symptoms of heart disease but whose cholesterol levels were elevated. ``It was felt that the evidence was not there to support this very aggressive management.''