Coronary atherosclerotic lesion: its characterization applying an atherometric system, using discriminant analysis

A given set of autopsies (total 2043) divided into high and low atherosclerosis groups (HAG, LAG) according to the primary cause of death 1171 and 872 cases, respectively, was studied by an atherometric system. The variables of this system characterize the pathomorphological changes, i.e. fatty streaks (X), fibrous plaques (Y) and severe (complicated and calcified) plaques (Z) of atherosclerosis. In the present study were also included two indices, stenosis (P) and benignity (B), applicable for estimation of the severity of the process. In order to verify the discrimination between the HAG and LAG groups the utility of the classification should be demonstrated. The three main branches of the coronary arteries, right (RC), left anterior descending (LAD) and left circumflex (LC), were examined. Qualitative and quantitative analyses of the different vascular changes were made by means of a digitizer coupled to a personal computer NEC 9801 (Japan). The data were processed in a computer EC-1040 (GDR). The multivariate statistical techniques, including discriminant analysis were used applying the "SPSS" commercial statistical package programme. The atherometric system proved to be useful to distinguish between HAG and LAG. Correct classification was in all cases greater than 70% except for LC (68%). The three variables X, Y and Z were capable to separate the groups. The stenosis and benignity indices proved to be the most effective for discrimination. The sign of benignity index discriminating function is always the same of the LAG. This variable is indeed one to indicate benignity. The coherence and consistency of the atherometric system developed was proved by discriminant analysis.