Yesterday In the New York Times, an article came out about the new guidelines published Tuesday by the American College of Cardiology and the American Heart Association, on when to put patients on cholesterol-reducing medications, like statins.
The first is titled “Experts Reshape Treatment Guide for Cholesterol,” the second, “New Cholesterol Advice Startles Even Some Doctors.” The first answers many of the pertinent questions about the new guidelines; the second is a pithy follow-up piece seemingly designed to “add controversy” (at least as far as I can tell). Except both seem to be missing the point: we’re still interested in knowing cholesterol levels, we’re just adding more data to the risk assessment procedure.
“The terminology that keeps coming to mind is ‘leap of faith,’ ” Dr. Lerner said. “You have to trust your doctor and the people who did the studies that they are correct that you don’t have to check LDL levels.”
Palm, meet face. You do still have to check LDL levels. I’ll explain.
Here’s the actual news: doctors and medical scientists have spent the past few years putting together new guidelines for treating people at risk of, and suffering from, heart disease. These guidelines came out recently, in a series of papers. The two most pertinent ones are (thankfully both open-source) here and here.
What seems to be rattling some people’s chains is that the study presenting guidelines on when to prescribe a class of widely-prescribed cholesterol-reducing drugs called statins may reduce the number of people who have to take them. In fact, it may all come out in a wash, but the people taking them will probably change demographically.
The four groups of people for whom statins are recommended are now as follows:
1. People with clinical heart disease (ASCVD: atherosclerotic cardiovascular disease).
2. Everyone with “bad cholesterol” (LDL) over 190 mg/dL.
3. People with bad cholesterol (but not necessarily heart disease) of 70-189 mg/dL who are 40 to 75 years old and have diabetes.
And, here’s the kicker:
4. People without heart disease or diabetes who are between 40 and 75 years old, with bad cholesterol of 70-189 mg/dL, AND have an estimated 10-year ASCVD risk of 7.5% or higher.
Why is this last one important? Because the second study just redefined exactly how they calculate that ten-year risk, lowering the risk for some, and raising it for others. Here’s a link to the new risk calculator they’re using, but one important thing is that they’re finally taking into account that all the previous data they were using were only about white people:
In collaboration with other NHLBI panels, the Work Group decided not to use this [previously determined] algorithm in its 2013 recommendations, because of its derivation in an exclusively White sample population and the limited scope of the outcome (in determining CHD alone). Rather, the Work Group derived risk equations from community-based cohorts that are broadly representative of the U.S. population of Whites and African Americans, and focused on estimation of first hard ASCVD events (defined as first occurrence of nonfatal myocardial infarction or CHD death, or fatal or nonfatal stroke) as the outcome of interest because it was deemed to be of greater relevance to both patients and providers.
Moreover, they’re using data about strokes as well, which, again, alters the risk playing field. So maybe fewer people are going to be taking statins, but also, new people are going to be taking them, too. (Also, am I the only one weirded out by the capitalization of “white”?)
To return to our previous point, it becomes fairly clear that doctors will need to continue to check LDL readings, to continue to exclude patients from category 2: people with LDL over 190mg/dL. So long as any category of people who need to take statins is decided solely by LDL levels, those readings will still be needed.
But now it means a more accurate risk assessment on top of that.
But of course change usually upsets people (and moreso when they don’t understand it). So why are they doing this?
Science is about always refining our data sets. It’s about testing hypotheses and replacing them when they’re outmoded or outdated. A risk assessment based only on white people really doesn’t pass muster, and adding in stroke risk factors helps refine it further (and there are more additions to the model than these, but damnit Jim, I’m a science blogger, not a doctor).
Lastly, I’d like to finally point out that the new recommendations state specifically that the person who makes the final decision is your doctor, and that they’re really, really only recommendations:
Guidelines attempt to define practices that meet the needs of patients in most circumstances and are not a replacement for clinical judgment. The ultimate decision about care of a particular patient must be made by the healthcare provider and patient in light of the circumstances presented by that patient.
So maybe, if you’re on statins or other cholesterol-reducing medications, talk to your doctor about the new guidelines, rather than a reporter.