PROGRESSION OF CORONARY-ARTERY DISEASE PREDICTS CLINICAL CORONARY EVENTS - LONG-TERM FOLLOW-UP FROM THE CHOLESTEROL-LOWERING ATHEROSCLEROSIS STUDY

Background Progression of coronary artery disease is assumed to be a s urrogate end point for clinical coronary events. Because no single met hod or measure for a coronary angiographic end point is uniformly acce pted as optimal, the utility and validity of surrogate end points for predicting clinical coronary events remain unsettled. Methods and Resu lts The Cholesterol Lowering Atherosclerosis Study randomized 162 nons moking, 40- to 59-year-old men with previous coronary artery bypass gr aft surgery to colestipol/niacin plus diet or placebo plus diet. Ather osclerosis change on 2-year coronary angiograms was evaluated by a con sensus panel and by quantitative coronary angiography (average per-sub ject change in percent diameter stenosis [%S] and minimum lumen diamet er [MLD]). With all three end points, the benefit of colestipol/niacin treatment on coronary artery atherosclerosis has been reported. Annua l follow-up for an average of 7 years (range, 6.3 months to 10 years) has been carried out on all subjects who completed the 2-year angiogra m. Clinical coronary events (need for revascularization, nonfatal acut e myocardial infarction, and coronary death) have been documented. Ris k of clinical coronary events was positively related to coronary lesio n progression for all three surrogate end points (P<.05). New lesion f ormation in bypass grafts (P=.02) and progression of mild/moderate les ions (<50%S) were predictive of clinical coronary events (P<.01). Chan ge in MLD contributed significantly to the prediction of clinical coro nary events beyond a model with %S alone (P<.05). Conclusions In this population of nonsmoking men with previous bypass surgery, both the co nsensus panel- and quantitative coronary angiography-based end points of coronary artery disease progression predict clinical coronary event s. Subjects who demonstrate greater coronary artery lesion progression have an increased risk of future clinical coronary events. Design of shorter, smaller trials of antiatherosclerotic agents is justified.