The American Heart Association (AHA) and American College of Cardiology (ACC) have released their 2013 Guidelines on the Treatment of Blood Cholesterol to Reduce Atherosclerotic Cardiovascular Risk in Adults.
The new Guidelines have not been without controversy, and include welcome revisions of previous guidelines, but add confusion by introducing a complicated calculator for use by Physicians, which is likely to grossly overestimate risk and unnecessarily expand the recommendations for statin use.
The central feature of the Guidelines is an abandonment of the time honoured LDL-C targets as a therapeutic strategy, with a focus on personalized Risk assessment, calling for a tailored treatment strategy, accompanied by efforts to improve lifestyle habits of patients before resorting to drug therapy.
The recognition that LDL-C does not accurately predict patient risk is welcome. The conventional strategy of “treating to target”, used over the past 15 years, has been acknowledged to be a practice unsupported by clinical evidence, and the dogma of “lowest is best” has been accordingly abandoned.
While the challenge for physicians will be to target cardiovascular risk, and not focus on cholesterol concentrations, the Guidelines add confusion by including total cholesterol numbers in the calculator equation for risk assessment.
The Guidelines specify “the Treatment of Blood Cholesterol to Reduce Atherosclerotic Cardiovascular Risk”, and imply thereby that blood cholesterol is a “disease” that needs to be “treated”.
An elevation of blood cholesterol is not a disease, and may reflect a host of pathological conditions that require medical intervention before resorting to cholesterol lowering methods.
Every cell in the human body manufactures cholesterol for health-sustaining purposes.
Since the pathological findings by Lande and Sperry in 1936, showing no correlation between atherosclerosis and cholesterol levels, there has been no supporting evidence for this widely held perception.
Atherosclerosis may occur in people regardless of high or low cholesterol levels, with extensive evidence showing increased risk in persons with low, rather than, high blood cholesterol levels.
The Guidelines define 4 groups of patient for whom “moderate or high intensity statin therapy” may provide benefit.
These are patients (a) with cardiovascular disease, (b)patients with LDL levels in excess of 4.9 MmoL/L, (c) Diabetic patients between ages 40-75 years, and (d) a group of people aged 40-75 years with a 10 year risk of CVD above 7.5%.
Many questions are likely to be raised about treatment for those in Group (d), since these represent a large body of healthy persons to whom statins will be offered, and may result in unwarranted treatment because of an overestimation of risk by 75% to 150%.
According to the calculator assessment, healthy white males over 62 years and healthy while females over 70 years will be candidates for statin therapy.
An added concern is that diabetic patients are encouraged to use statins, in spite of the ever present risk for statin induced diabetes, and little has been said about the greater risks linked to an excess of dietary polyunsaturated fats and carbohydrate intake.
Translating the new Guidelines into performance measures will be a challenge for all treating physicians as an old paradigm is abandoned and a more personalized response to patient care is called for.
Dr. Neville Wilson.
The Leinster Clinic.