Report of Committee on Grading Lesions, Council on Arteriosclerosis, American Heart Association. Grading human atherosclerotic lesions using a panel of photographs.

The American Heart Association's Committee on Grading Lesions of the Council on Arteriosclerosis has devised a method of grading the severity of atherosclerosis in human coronary arteries and aortas. The method uses two series of color photographs of arteries arranged in increasing severity of atherosclerosis. The Committee tested the method for inter-observer reproducibility by exhibiting the panel at two national scientific conventions and inviting visitors to grade a set of arteries with the panel. The test demonstrated a reasonable degree of inter-observer reproducibility despite a wide range of experience and disciplinary background. Inter-observer variability decreases with increasing experience in working with atherosclerotic lesions. Training graders who participate in a study may reduce inter-observer bias. For populations with predominantly less or predominantly more atherosclerosis, the investigator should construct special panels with different ranges of severity. The Committee revised the panel in the light of the results of the two exhibits and the comments of users in a field trial. The revised panel provides seven possible scores for each coronary artery and for each aorta. This panel provides a relatively simple and speedy quantitative method of comparing autopsy data on atherosclerosis among many kinds of studies and has the added advantages of facilitating comparisons between different geographic locations and different times.