A multitude of coronary angiographic trials have been conducted using various endpoint measures based on repeated coronary angiograms. Relative to coronary event trials, angiographic trials require both a smaller sample size and reduced trial length. While such trials have assumed that angiographic endpoints are valid surrogate measures for clinical coronary events, this assumption has not been completely tested. Although several coronary angiographic endpoints are available for trial outcomes, no single method has been uniformly accepted as optimal. Because of this, the utility and validity of coronary angiographic progression for predicting future clinical coronary events remains unsettled.