[Limitation of atherosclerosis in coronary arteries with pravastatin (PLAC 1)]

PLAC 1 is a double-blind, randomized, placebo controlled trial assessing the efficacy of monotherapy with an HMG CoA reductase inhibitor (pravastatin) in altering the atherosclerotic process. This trial was an angiographic trial undertaken in the United States and was completed in early 1994. Despite the fact that angiographic end-points were the prime focus during the planning and execution of the trial, significant impact was seen in the area of clinical events, particularly fatal and nonfatal myocardial infarctions. The latter were significantly reduced in the treated patients. These results were paralleled by a significant slowing of progression in the treated patients. Importantly, the angiographic effects were predominant in prevention of new lesion formation and in slowing the progression of mild/moderate lesions less than 50% diameter stenosis at baseline. Current concepts suggest that the latter two categories of lesions are the most important in linking angiographic outcomes with clinical events. PLAC 1 is the first trial to concomitantly show statistically significant effects in clinical end points and angiographic end-points in the category of new and/or mild stenoses. These results are compatible with the concept of plaque stabilization.