Making sense of the statin guidelines

For years, doctors prescribed cholesterol-lowing statins based largely on cholesterol test results. The goal was to lower total cholesterol to under 200 mg/dL, and LDL (bad) cholesterol to under 100 mg/dL. But in late 2013, new guidelines on statin use issued by the American Heart Association (AHA) and the American College of Cardiology (ACC) proposed a major change to that strategy.

These guidelines shifted from a numbers-based approach to a risk-driven approach. Instead of aiming for a specific cholesterol value, doctors were urged to look at a person's entire cardiovascular risk profile when considering treatment. This is a reasonable approach that can help simplify how doctors think about whom to treat.

The 2013 guidelines were met with more than the usual criticism, however. In fact, they've generated considerable debate over their departure from the approach of earlier guidelines. The new guidelines don't, for example, specify normal and abnormal levels for total cholesterol, LDL, HDL, and triglycerides, as past versions have done. Perhaps the best way to look at these guidelines is as a scientific statement reviewing what has been definitively established to date.

Who should take a statin?
The 2013 guidelines recommend a daily statin for individuals who fall into the following four categories:

anyone age 21 or older with a very high level of harmful LDL cholesterol (190 mg/dL or higher)

anyone who has cardiovascular disease, including stable or unstable angina (chest pain with exercise or stress); has had a heart attack, stroke, or transient ischemic attack ("ministroke"); has peripheral artery disease; or has had bypass surgery or angioplasty to treat a cholesterol-clogged artery

anyone age 40 to 75 who has diabetes

anyone age 40 to 75 who does not have cardiovascular disease but has a greater than 7.5% chance of having a heart attack or stroke or developing another form of cardiovascular disease in the next 10 years (as determined using the online risk calculator cited below).

That last category represented a major shift. In principle, if doctors follow the guidelines and start treating people who don't have heart disease but are at risk for it, several million more people will take a statin every day. It's not yet clear if that has happened, however, as studies examining this question have offered differing results.