Newly revised guidelines for treating cholesterol to reduce cardiovascular disease risk were released in November by the American Heart Association (AHA) and American College of Cardiology (ACC). The new guidelines de-emphasized achieving target numbers for LDL-C (low density lipoprotein cholesterol), the harmful form of cholesterol. Emory preventive cardiologist Peter Wilson served on the AHA/ACC task force that formulated the new guidelines. He drew on a wealth of research experience, including 20 years as director of laboratories at the Framingham Heart Study in Massachusetts, as well as clinical experience at the Emory Clinic and the Atlanta VA Medical Center Lipid Clinic.
Why did an update become necessary?
Cholesterol-lowering medications had become more potent over the past decade. More information on their safety and efficacy was available, but that evidence had not been integrated into the recommendations. Many statins have recently gone off patent, so their cost has gone down—atorvastatin [Lipitor] is a prominent example of a lipid-lowering drug that now costs much less. And we needed to evaluate the results of clinical trials involving statins—statins vs. placebos, low dose vs. high dose, statin plus a second drug vs. statin alone.
In addition, several questions about testing and evaluation had come up. Doctors want to know: "How low does cholesterol need to go? Do you need do a CRP (C-reactive protein) test? What about coronary artery calcium (CAC) testing?"
The NIH Heart, Lung, and Blood Institute directed us to use the Institute of Medicine approach, which is sort of a "guideline for guidelines." They have a hierarchy of evidence, with randomized controlled clinical trials carrying the greatest weight, and a mandate to limit the number of recommendations that are "expert opinion."
What is considered expert opinion?
For example, the advice to get some patients' LDL-C below 70 mg/dL. When that was promulgated in 2004, there was no hard evidence for it. There was one study with data on people who had LDL lower than 70 mg/dL, where you could infer some possible benefit. A lot of providers jumped on that and said, "I'll get everybody under 70 if I can! If it's safe and tolerated, why not?"
How will the new guidelines affect patients with different profiles?
Let's take a high-risk case—a middle-age male smoker with high blood pressure. His LDL-C level is 130 mg/dL. This is an "average Joe" LDL. He had a heart attack and is sent home from the hospital on a statin. Before, the goal was to get the patient's LDL-C below 100 mg/dL. The doctor would say, we'll see you in six weeks. When the patient came back, the doctor would ask about statin side effects and look at the LDL-C levels. If there had been some progress, the patient would be told to keep up the good work. But this reflects a short-term focus. Sometimes you see people at six months post-heart attack and they're not on their medicines. Patients ask: "Is this lifelong?" Well, yes, unless there's a big change. Unless you become a low-fat, low-cholesterol vegetarian, you're probably not going to be able to make great progress in lowering LDL-C without medicine. Now, let's take that same man under the new guidelines. An LDL-C of 130 is clearly too high, so he'd be put on a high-potency statin. A post-heart attack patient would probably get rosuvastatin (Crestor) or atorvastatin (Lipitor). If he can't tolerate either of those, we'll move on to other options.