Calculator for risk factors may be flawed
We need cholesterol for our cells to function properly, but when we have too much it can have deleterious effects on our hearts. We know that higher LDL “bad” levels and total cholesterol levels may be dangerous and that higher HDL cholesterol levels are good. I am not telling you anything new. However, new guidelines for cholesterol were just released through a joint effort by the American Heart Association and American College of Cardiology (J Am Coll Cardiol. 2013, online Nov. 15; Circulation. 2013, online Nov. 12).
The new guidelines call into question the targets physicians have been using to treat patients with elevated LDL levels. We had been treating patients to a target LDL of either <100 mg/dl or <70 mg/dl, depending on the patient’s status. Instead of focusing on cholesterol targets, these new guidelines suggest that physicians use a risk calculator to assess a patient’s chance of having a cardiovascular event, such as a stroke or a heart attack, except when LDL >190 mg/dl. For these patients, you treat based on the high number.
There are four groups that should be treated, according to the new guidelines. In the most debatable category, healthy patients with a calculated 10-year cardiovascular risk of >7.5% should receive moderate- to high-intensity treatment with cholesterol-lowering medications, such as statins. In patients with cardiovascular disease, higher levels of medication should be used to reduce LDL by 50% or more.
The idea is to treat the patient overall, not to aim for a specific target. To this end, the guidelines suggest that, once statins are prescribed, LDL levels should not be monitored on a regular basis. Without monitoring, though, how will you know whether the treatment is having an effect?
One of the study authors gives an example: if a patient is on cholesterol-lowering medication and is following appropriate lifestyle modifications, but has an LDL that is slightly above the goal, then treatment should not be intensified (medpagetoday.com). The guidelines help to prevent the use of nonstatin drugs that reduce levels of LDL, but that have not shown clinical benefit.
The guidelines also suggest that someone who only has mildly elevated cholesterol levels and no other risk factors, including age, does not warrant medication. This sounds reasonable so far, right? Unfortunately, it is not as clear-cut as it sounds. This approach dramatically changes the paradigm in which physicians have been operating for years.
Medical community reactions
Cholesterol — whether to treat and when — suddenly has become a highly controversial issue. There are two camps within the medical community: one believes these guidelines will help define the patients who are prime subjects to be treated either for primary prevention (prior to a cardiovascular episode) and secondary prevention (those who have had cardiovascular events); the other worries this may result in overtreatment.
The risk factors in the new calculator include age, sex, systolic blood pressure, total cholesterol levels, LDL levels, smoking status, high blood pressure treatment and diabetic status. This seems simple enough, but like most things in medicine, whenever something is significantly overhauled, there are potential problems. I have to be forthright and say after reading the commentary, I am leaning toward the camp that is skeptical of the guidelines. Let’s look at the potential problems.
Potential overuse of statins
The cardiovascular risk of >7.5% for treatment is significantly lower than what it has been in the past, 10% to 20%. According to an editorial written in a prominent journal, two physicians calculate that it may increase the number of healthy patients treated with statins by 70%. They point out that statins are ineffective in death reduction if cardiovascular risk is less than 20% (BMJ. 2013;347:f6123). Also they note that it takes 140 patients treated with statins to prevent one heart attack or stroke.
In addition, using the calculator, someone can have normal cholesterol levels and be put on statins based on other factors, such as age, race and sex. Therefore, many more patients could be treated with medications, most likely statins, than in the past.
In a New York Times article published Nov. 18, entitled “Flawed Gauge for Cholesterol Risk Poses a New Challenge for Cardiologists,” the authors note that the online calculator may overestimate the risk percentages. Paul Ridker, M.D., and Nancy Cook, M.D., both Harvard Medical School physicians, tested the calculator by using large trials, such as the Women’s Health Initiative Observational Study, determining that risk is inflated by a mean of 100%. This is because the calculator’s design is based on studies that are over a decade old, many of them from the 1990s.
Demographics have changed since then: we have fewer smokers; heart attack and stroke risk has become similar in men and women, whereas men were at higher risk in the past; and cardiovascular disease incidence has decreased. The calculator also assumes that risk moves in a linear fashion, so as the blood pressure is elevated, risk increases in direct proportion, but it is not that simple.
The suggested treatment with statins is moderate or high intensity. The problem with this approach is that the higher the intensity, the greater the risk of side effects, such as increased risk of diabetes (Arch Intern Med. 2012;172:144-152), fatigue (Arch Intern Med. 2012;172:1180-1182), muscle cramps and pain (Pharmacotherapy. 2010;30:541-553), as well as cataracts (Optom Vis Sci. 2012;89:1165-1171). The FDA recently warned about using high statin doses and muscle pain (fda.gov).
Lifestyle and anthropometrics
The risk calculator does not incorporate lifestyle, whether positive or negative, or anthropometrics, such as waist circumference and BMI.
To boot, there are no clinical trials that show the risk calculator is beneficial. It has never been examined in this way, and there have been no new trials that require altering the guidelines in this way.
Guidelines, of course, are just that; they are at the discretion of the physician to follow and discuss with the patient, but ultimately treatment decisions should be made by the patient and physician in partnership. To their credit, the authors of the guidelines acknowledge this very same point.
If you do take statins, don’t become complacent about lifestyle changes — nutrient dense diet, exercise, stress management and quit smoking — and think statins are a silver bullet. On the positive side, giving statins for risk reduction may be more beneficial than just lowering cholesterol numbers. Also, the new guidelines may make physicians hesitant to give drugs that just lower numbers, but that have never shown any clinical benefit.
Dr. Dunaief is a speaker, author and local lifestyle medicine physician focusing on the integration of medicine, nutrition, fitness and stress management. For further information, go to the website www.medicalcompassmd.com and/or consult your personal physician.