The nation’s leading heart organizations, the American Heart Association and the American College of Cardiology, released new guidelines Tuesday that will fundamentally reshape the use of cholesterol-lowering statin medicines now prescribed for a quarter of Americans older than 40.
Patients on statins will no longer need to lower their cholesterol levels to specific numerical targets monitored by regular blood tests, as has been recommended for decades. Simply taking the right dose of a statin will be sufficient, the guidelines say.
The new guidelines, based on a four-year review of the evidence, also simplify the current complex, five-step process for evaluating who needs to take statins. In a significant departure, the new method counts strokes as well as heart attacks in its risk calculations, a step that will likely make more people candidates for the drugs.
The new approach divides people needing treatment into two broad risk categories. Those at risk because, for example, they have diabetes or have had a heart attack should take a statin except in rare cases. People with extremely high levels of the harmful cholesterol known as LDL — 190 or higher — should also be prescribed statins.
In the past, people in these categories would have been put on statins, but they also would have been told to lower their LDL to 70, something no longer required.
Everyone else should be considered for a statin if their risk of a heart attack or stroke in the next 10 years is at least 7.5 percent. Doctors are advised to use a new risk calculator that factors in a person’s blood pressure, age and whether they smoke, among other things.
It is not clear whether more or fewer people will end up taking the drugs under the new guidelines, experts said. Many women and African-Americans, who have a higher-than-average stroke risk, might find themselves candidates for treatment, but others taking statins only to lower LDL cholesterol to target levels might no longer need them.
“Now 1 in 4 Americans over 40 will be saying, ‘Should I be taking this anymore?’ ” said Dr. Harlan Krumholz, a cardiologist and professor of medicine at Yale who was not on the guidelines committee.
The previous guidelines put such a strong emphasis on lowering cholesterol levels by specific amounts that patients who did not hit their target levels just by taking statins often were prescribed additional drugs like Zetia. But the new guidelines say doctors should no longer prescribe those extra medicines because they have never been shown to prevent heart attacks or strokes.
The guidelines are part of a package of recommendations to reduce the risk of heart attacks and strokes that includes weight loss, lifestyle changes like moderate exercise and a healthy diet.
But its advice on cholesterol is the flashpoint, arousing the ire of critics who say the authors ignored evidence that did not come from gold-standard clinical trials and should also have counted less rigorous but compelling data.
Critics also question the use of a 10-year risk of a heart attack or stroke as the measure for determining who should be treated.
Many people will have a lower risk simply because they are younger, yet could benefit from decades of taking statins that keep their cholesterol levels low, they say.
Dr. Daniel Rader, the director of the preventive cardiovascular medicine and lipid clinic at the University of Pennsylvania, points to studies of people with genes giving them low LDL levels over a lifetime, saying that their heart-attack rate is greatly reduced.
He and other experts also worry that without the goad of target numbers patients and their doctors will lose motivation to control cholesterol levels.