Clinical Trials
The two most recent primary prevention trials, the Lipid Research Clinics (LRC) Coronary Primary Prevention Trial and The Helsinki Heart Study significantly reduced the incidence of CAD. The LRC trial used the drug Cholestyramine and the Helsinki study used the drug Gemfibrozil. Since these trials the more powerful HMG CoA Reductase inhibitors are now available making therapy more tolerable and effective.
Regression of atherosclerotic lesions is seen in patients undergoing aggressive cholesterol lowering. The first major secondary prevention trial to demonstrate this was the Cholesterol Lowering Atherosclerosis Study (CLAS) using the drugs colestipol and niacin. This was followed by the Familial Atherosclerosis Treatment Study using niacin/colestipol and lovastatin/colestipol. Since then, several other trials have confirmed the findings that not only can aggressive cholesterol lowering angiographically cause lesions to regress, but can also dramatically reduce the occurrence of clinical events. Of note, regression occurs primarily in patients whose LDL cholesterol has been reduced to less than 100 mg/dl. Most important, the Scandinavian Simvastatin Survival Study (4S trial) has recently shown that cholesterol lowering with medication when applied to patients with atherosclerosis not only decreases coronary events, but can prolong survival as well.
