Therapeutic Effects of Lowering Cholesterol
in: CURRENT Medical Dx & Tx 2014, Fifty-Third Edition > Chapter 28. Lipid Disorders
Robert B. Baron, MD, MS
Reducing cholesterol levels in healthy middle-aged men without CHD (primary prevention) reduces their risk in proportion to the reduction in LDL cholesterol and the increase in HDL cholesterol.
Treated adults have statistically significant and clinically important reductions in the rates of myocardial infarctions, new cases of angina, and need for coronary artery bypass procedures.
Rosuvastatin … JUPITER … a combined end point of myocardial infarction, stroke, revascularization, hospitalization for unstable angina, or death from cardiovascular causes in both men and women. The NNT for 1 year to prevent one event was 169.
Primary prevention studies have found a less consistent effect on total mortality.
The JUPITER trial … reduction in death from any cause. The NNT for 1 year was 400.
In patients with CHD, the benefits of cholesterol lowering are clearer.
The NNT to prevent a non-fatal myocardial infarction or a coronary artery disease death in these three studies were between 12 and 34. Aggressive cholesterol lowering with these agents causes regression of atherosclerotic plaques in some patients, reduces the progression of atherosclerosis in saphenous vein grafts, and can slow or reverse carotid artery atherosclerosis.
Meta-analysis suggests that this latter effect results in a significant decrease in strokes.
Results with other classes of medications have been less consistent.
For example, gemfibrozil treatment …
The disparities in results between primary and secondary prevention studies highlight several important points.
The benefits and adverse effects of cholesterol lowering may be specific to each type of drug; the clinician cannot assume that the effects will generalize to other classes of medication.
Second, the net benefits from cholesterol lowering depend on the underlying risk of CHD and of other disease.
In patients with atherosclerosis, morbidity and mortality rates associated with CHD are high, and measures that reduce it are more likely to be beneficial even if they have no effect—or even slightly harmful effects—on other diseases.