Cholesterol-lowering drugs called statins are most helpful for people whose heart disease risk is largely genetic, according to a meta-analysis published today in The Lancet.

The results will help doctors decide who will benefit from statin drugs, which reduce the amount of cholesterol the body produces.

“Current clinical guidelines base treatment indications, in part, on the estimated 10-year risk of having an event [like a heart attack or stroke]. It is possible that a genetic score such as this one might help refine these risk estimates in the future,” study author Dr. Nathan Stitziel, Ph.D., a cardiologist at Washington University in St. Louis said in a press statement.

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Statins, such as Lipitor and Crestor, were once hailed as miracle drugs and have been widely prescribed.

In recent years, cardiologists have moved to make sure that the drugs aren’t over-prescribed.

In 2013, the American Heart Association (AHA) changed its guidelines for how doctors should determine who gets statin drugs. Instead of focusing on those who have “bad” cholesterol levels over a certain threshold, doctors should look at a person’s overall risk profile.

“The current situation is that statins are over-prescribed for a segment of population, which is people who are actually at low risk. But I think the larger problem is that statins are actually under-prescribed because of this view that we should only look at cholesterol. We’re under prescribing for many people who are at risk when you look at their whole profile,” said Dr. Donald Lloyd-Jones, a spokesperson for the AHA who helped write the 2013 guidelines.

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The new findings make the case that a more holistic approach makes sense, and that genes play an important role in determining risk. Genetics account for 30 to 60 percent of the variation in the risk of a heart attack or stroke.

The new analysis included data from 48,421 participants in cardiovascular studies. The participants were divided into low, medium, and high genetic risk groups based on 27 known genetic variants that influence heart disease.

The genetic screening isn’t available in most doctors’ offices.

The researchers looked at real medical outcomes over time. They found that patients with a greater genetic risk of cardiac “events” who took statins saw their risk slashed three times as much as those with a lower genetic risk who also took the drugs.

The researchers reached this conclusion by comparing the number of heart attacks and strokes in patients who took statins to the number of these events in patients in the same genetic risk group who did not.

Because patients with a lower genetic risk of a cardiovascular event get less benefit from statins, doctors may be less likely to prescribe statins to these patients in the future.

“They study parallels the approach we took, which is to think about treating based on risk of the individual. It’s the same approach, they just used a different model. It’s not ready for clinical prime time but it points the way to what may be the future of this sort of personalized medicine,” Lloyd-Jones said.

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