Wow! Who would have thought so many people were so passionately interested in cholesterol-lowering drugs? I guess it's understandable that the newly promulgated guidelines have stirred so much controversy, but I'd like to separate the facts from the fears.
Let's start with what's really new about these new guidelines. As accurately noted in the first New York Times article on this topic:
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.
This is because the panel reviewing the evidence recognized that although there is strong evidence that statins reduce the risk of cardiovascular disease, there isn't evidence that treating to any specific "target" cholesterol is helpful. Thus, they say: if you and your doctor determine that you ought to take statins to prevent heart disease, take the appropriate and tolerated dose and don't worry about monitoring your cholesterol levels.
The other major point is that the appropriateness of using statins shouldn't be determined simply by the cholesterol level, but in the context of an individual's overall level of cardiovascular disease risk. This isn't really a change -- the current guidelines emphasize overall risk assessment as well -- but it is more strongly emphasized in this new report. Moreover, while the current guidelines emphasize treatment for those whose 10-year risk of cardiovascular disease is 10 percent or more, the new report suggests lowering the bar to 7.5 percent or more. This would probably put many more people into the "need statin" bucket, raising understandable, satirical (and sometimes conspiratorial) concerns that Big Pharma is driving this to get more people on their drugs.
And then it all hit the fan when problems with the online risk calculator were identified, overestimating the risk for some folks, thereby putting even more people into that "need statin" bucket. (What is it about health professionals and websites and calculators, anyway?)
Here's my take on this, categorized into some general principles:
1.High cholesterol is a risk factor, not a disease.
While we have tended to obscure this fact by saying things such as "I am treating my cholesterol," we care about cholesterol levels only because they help predict future risk of heart attack and stroke. Those are the things we really care about -- the cholesterol in your blood is just a clue that you're at increased risk. Unfortunately, even doctors get confused about this point, as exemplified by the opening of this article about how startled doctors are by these new guidelines. "Steven L. Zweibel has been taking a statin drug to lower his cholesterol for seven years. It has worked, and he has suffered no problems or side effects."
Think about that statement, "It has worked." Yes, you can know if your cholesterol is lower, but lowering cholesterol isn't the goal, preventing heart attacks is. If the reason to take statins is to lower your risk of cardiovascular disease, then there's no way to know if "it has worked." (If you haven't had a heart attack yet -- well, maybe you wouldn't have even without the statin. If you have had a heart attack -- well, maybe you would have had one sooner.) By the way, there are drugs known to lower cholesterol that increase the risk of death. That isn't what you want, is it?
2.The greater your overall risk for a disease, the greater the benefit/risk ratio of trying to prevent that disease.
This fact is almost intuitive, but is worth thinking about. Say you've got a treatment that reduces risk by 50 percent with a one percent risk of significant side effects. Sounds pretty good, right? Well, it is if your risk of getting the disease is pretty high -- say, 20 percent, where reducing the risk by 50 percent means cutting it from 20 percent to 10 percent. So 10 percent of people will benefit, and only 1 percent will have significant side effects. But if your risk is low -- say, two percent -- then cutting it in half helps only one percent of people taking the drug, while one percent will have side effects. Not so good, eh?
Of course, figuring out your risk is challenging. As our resident Bronx Philosopher-General, Yogi Berra is remembered as saying: "It's hard to make predictions, especially when they involve the future." All such "calculators" are based on projections, statistical models and yes, old data, but such estimates aren't precise, and they aren't determinative. They just give you a relative sense of where you are on the risk curve.
3.Guidelines are only guidelines, not rules. They should be followed mindful of a patient's values, a doctor's judgment and how an individual patient fares if treatment is prescribed.
So this is the dirty little secret: if guidelines say you should do something, it doesn't mean you must. Take the most controversial of these new guidelines: "Adults 40 to 75 years of age with LDL-C 70 to 189 mg/dL and without diabetes and an estimated 10-year ASCVD risk ≥7.5% should be treated with moderate- to high-intensity statin therapy."
Even if the calculator were functioning properly and my own risk were greater than 7.5 percent (it's currently a little lower than that), I probably wouldn't choose to take statins right now, just because I tend to prefer a "less is more" approach to medication (and so does my doctor). If my primary care physician thought I should, however, I'd certainly be open to discussing it -- and if I chose to try a statin, I'd find out if it made me feel sick or caused troubling side effects. And if it did, I'd stop taking it.
Listen: preventive medicine is a tricky business. It involves taking healthy people and doing stuff to them to keep them healthy. I appreciate (and share) concern about Americans' love affair with pills, and I applaud those who espouse healthy lifestyles -- but pills are easier to study and easier to take. And for those who say this is tantamount to putting almost everyone on statins: ever heard about fluoride in drinking water? Folic acid in the grain supply? How about the "polypill" for all adults in low- and middle-income countries?
Whether we're talking about broad public health prescriptions or individual prescriptions, it's all a matter of benefit versus risk, and that requires a careful look at the evidence. Doctors and patients alike may find themselves understandably confused by changing guidelines and the uncertainty inherent in predicting the future. Assuming they're of sound mind, patients do have choices: take statins if they meet the new risk threshold, then monitor closely for potential side effects and stop if necessary; find a non-statin alternative; or choose no drug therapy in favor of a healthier diet and more exercise. Whatever patients choose, they'll have to accept that no decision insulates them from uncertainty.
This post was originally published on The Doctor's Tablet, the blog of Albert Einstein College of Medicine.