The old cholesterol guidelines included a risk assessment tool, but it did not play nearly as prominent a role as the new risk calculator. The new tool is based on additional population-wide data, which has been another matter for debate (for instance, about whether the data, mostly from the 1990s, are representative of the general population today). For the first time, it includes risk for stroke and takes into account data about African Americans, who are at higher CVD risk; it also utilizes better data about women.
Who is supposed to use the risk calculator? Everyone ages 40 to 75, except those with pre-existing CVD, diabetes or very high LDL (who automatically should take statins) and those already on statins. You fill in some basic information, such as your age, sex, race, total and HDL (“good”) cholesterol and systolic blood pressure (the first number), as well as whether you smoke.
If your 10-year risk is 7.5 percent or higher, the guidelines advise that you take a statin. It’s estimated that 33 million Americans ages 40 to 75 exceed that threshold.
Critics claim that the calculator significantly overestimates risk and will potentially lead to statin use by millions of healthy Americans who don’t really need the drugs. In particular, there’s concern that even though most heart attacks and strokes occur in older people, the new risk score is overly influenced by age. As a result, nearly all men over 63 and women over 70 will score above the 7.5 percent cutoff and be recommended statins, even if they have very good cholesterol numbers and no other risk factors. The guidelines acknowledge this, as well as the likely overestimation of risk among Hispanics and Asian Americans.
At the same time, the calculator’s algorithms could exclude statin therapy for some people who may benefit, particularly those with CVD risk factors not included in the calculator, such as obesity or a family history of premature CVD, and people with moderately high LDL (between 160 and 190) but no other risk factors.
The guidelines say that even those who score between 5 and 7.5 percent may be candidates for statins if they have other risk factors. In these and other people for whom there’s uncertainty about treatment, the guidelines suggest that four other factors may be considered—family history, LDL over 160, high blood levels of C-reactive protein (a marker for inflammation), elevated coronary calcium score (a marker for CVD risk) and peripheral artery disease. In effect, if it’s unclear whether you should take a statin, these may serve as a tie-breaker in making the decision. Some critics believe that additional factors, such as elevated triglycerides and other blood markers of CVD risk, should also be considered.
One thing is clear: If you score above the 7.5 percent cutoff largely because you smoke or have high blood pressure, the best thing you can do is quit smoking or control your blood pressure. That may be enough to get you below the cutoff, so you needn’t start on statin therapy. The guidelines do say that before doctors prescribe a statin, they should talk with their patients about lifestyle changes that could help reduce their risk. However, it’s easy to lose sight of this, partly because the diet/lifestyle and obesity guidelines are separate from the cholesterol guidelines.