Cholesterol Lowering Therapy
Super-sizing Cholesterol Lowering Therapy: Are There Benefits?
What is the problem and what is known about it so far?
Lowering total cholesterol slows the progression of heart disease. The reduction of LDL "bad" cholesterol is especially important in removing the amount of fatty plaques that deposit within arteries. Taken consistently, statin medications have proven to be effective in lowering LDLs and increasing HDLs ("good cholesterol") thereby slowing the progression or development of coronary (heart) disease. At this time, a recommended LDL of less than 100 is recommended for patients with known heart disease. However, the level of LDL cholesterol control needed to achieve significant protective effects is unknown.
Why did the researchers do this particular study?
The purpose of this study was to compare the effects of a moderate versus intense cholesterol lowering medication program in reducing cholesterol plaque build-up in the coronary arteries.
Who was studied?
654 patients between 30-75 years old participated in this study. All participants had at least one vessel that was narrowed by greater than 20 percent as shown by angiography performed for a clinical indication. Of these patients, 502 completed the study in its entirety.
How was the study done?
This was a double-blind controlled trial. Patients were randomly assigned to a moderate-lipid lowering group of 40 mg pravastatin or an intensive lipid-lowering group of 80 mg atorvastatin. Intravascular ultrasound examinations were performed at the initiation of the study and after 18 months of treatment. Coronary angiograms were also repeated at 18 months.
What did the researchers find?
Patients on atorvastatin (the more aggressive treatment program) were found to have greater reductions in overall LDL cholesterol levels, total cholesterol, triglycerides and C-reactive protein. The atorvastatin group showed a reduction in cholesterol plaque volume within their coronary arteries, whereas the patients in the pravastatin (the less aggressive treatment option) group were found to have an increase in plaque size. Both treatments were well-tolerated.
What were the limitations of the study?
Assessment of cholesterol plaque burden by intravascular ultrasound is a relatively new technique and thus its role as a clinical indicator is uncertain. As few participants died or had myocardial infarctions (heart attacks) the effects of these two statin drugs on these outcomes could not be assessed. A larger patient population size and longer study would be necessary to produce significant results.
What are the implications of the study?
Intensive cholesterol lowering regimens effectively reduce total and LDL cholesterol, and triglycerides. However, more study is needed to correlate the role of aggressive therapy in slowing progression of coronary disease and reducing the incidence of heart attacks.
Summarized by Winifred Lee, College of Medicine, University of Vermont.
Summarized from "Effect of Intensive Compared With Moderate Lipid-Lowering Therapy on Progression of Coronary Atherosclerosis: A Randomized Controlled Trial". Nissen, Steven E. et al. The Journal of the American Medical Association, March 3, 2004, Volume 291, Number 9, Pages 1071-1080.
