MONDAY, May 15 (HealthDay News) -- America's top experts in heart disease have issued new guidelines on helping people with the illness avoid more cardiovascular trouble.

The guidelines, issued Monday by the American Heart Association and the American College of Cardiology, apply to a wide range of patients: Those who have had heart attacks, those with the variety of heart problems called acute coronary syndromes, and those with other blood vessel conditions such as peripheral arterial disease.

The recommendations were issued in a joint statement by the two organizations and have also been endorsed by the National Heart, Lung, and Blood Institute.

The new guidelines come as the result "of a number of new trials completed since our last recommendations were issued," said Dr. Sidney S. Smith, a professor of medicine at the University of North Carolina and chairman of the group that drew up the report.

Some recommendations in the guidelines, which update those issued five years ago, are new. For example, the new rules advise that anyone with heart disease get a flu shot every year.

Other recommendations simply highlight tried-and-true means of reining in risk.

One advisory: people diagnosed with heart disease should get 30 to 60 minutes of moderate exercise, such as brisk walking, at least five, and preferably seven, days a week. The old guidelines called for this type of exercise three or four days a week.

The old guidelines held that blood levels of LDL cholesterol, the bad kind that clogs arteries, should stay below 100 milligrams per deciliter (mg/dL) and, ideally, below 70 mg/dL for very high-risk patients. According to the new advisory, those guidelines are now recommended for all people with established heart disease.

Levels of all blood fats, excluding HDL cholesterol -- the good kind that helps keep arteries clear -- should be kept under 100 milligrams per deciliters, the new guidelines say.