Additional searches cross- referenced these topics with the subtopics of clinical trials, secondary prevention, atherosclerosis, and coronary/cerebral/pe- ripheral artery disease. These searches were limited to studies, reviews, and other evidence conducted in human subjects and published in English. In addition, the writing group reviewed documents related to the subject matter previ- ously published by the AHA, the ACCF, and the National Institutes of Health. With regard to lipids and dyslipidemias, the lipid reduction trials published between 2002 and 200618,25,166 168 included .50 000 patients and resulted in new optional therapeutic targets, which were outlined in the 2004 update of the National Heart, Lung, and Blood Institute s Adult Treatment Panel (ATP) III report.169 These changes defined optional lower target cho- lesterol levels for very high-risk coronary heart disease (CHD) patients, especially those with acute coronary syndromes, and expanded indications for drug treatment. Subsequent to the 2004 update of ATP III, 2 additional trials26,27 demonstrated cardio- vascular benefit for lipid lowering significantly below current cholesterol goal levels for those with chronic coronary heart disease. These trials allowed for alterations in the 2006 guide- line, such that low-density lipoprotein cholesterol (LDL-C) should be ,100 mg/dL for all patients with CHD and other clinical forms of atherosclerotic disease, but in addition, it is Table 2. Applying Classification of Recommendation and Level of Evidence A recommendation with Level of Evidence B or C does not imply that the recommendation is weak. Many important clinical questions addressed in the guidelines do not lend themselves to clinical trials. Although randomized trials are unavailable, there may be a very clear clinical consensus that a particular test or therapy is useful or effective. 