RESUMO
In 2043 autopsies divided into the high (HAG) and low (LAG) atherosclerosis group a set of variables of a new atherometric system (AS) was used to characterize the atherosclerotic lesion (AL) in the circle of Willis arteries: fatty streaks (X), fibrous plaques (Y), severe plaques (Z), index of stenosis (P) and index of benignity (B). Principal component analysis identified a first component of severity (Y, P and Z) and a second component of benignity (X and B). Fibrous plaques play the main role in the severity of AL in the circle of Willis. The new AS proved its usefulness in characterizing the state of AL, whereas discriminant analysis and AS distinguished between the HAG and the LAG. The classification was correct in 74.5% and 76.5% when using three (X, Y, Z) and five (X, Y, Z, P, B) variables, respectively.
Assuntos
Círculo Arterial do Cérebro/patologia , Arteriosclerose Intracraniana/patologia , Arteriosclerose/patologia , Análise Discriminante , Humanos , Análise Numérica Assistida por ComputadorRESUMO
A new approach to study the atherosclerotic lesions (AL) applying a vectorial system is presented. The "lesional state vector" (LSV) is formed by using as vectors the three main types of AL, e.g. fatty streak, fibrous plaque and severe plaque (complicated and calcified considered together) as the coordinates. This vectorial representation is part of a biometric system described in 1982 by Carlevaro and Fernández-Britto, to characterize the AL in any vascular sector or group of patients. The LSV is a suitable tool to study the AL since it conserves all the information available as primary data and it is extremely useful for comparative studies applying different statistical techniques, including multivariate approaches. To demonstrate its advantage, we studied the coronary vessels (right, left anterior descending and left circumflex arteries), the cerebral arteries (circle of Willis) and the aorta (thoracic and abdominal segments) in 2,043 autopsies performed during 5 years (1981-1985). The patients were classified according to the primary cause of death, as high atherosclerotic (HAG) or low atherosclerotic groups (LAG), comprising 1,171 and 872 cases, respectively. Qualitative and quantitative gross analysis were done by a digitizer joined to a personal computer (NEC 9801, Japan). These data were processed on computer ES 1040, GDR. The statistical techniques applied (including the multivariate analysis) were those available in the Statistical Package for Social Sciences (SPSS). Applying the LSV to the arteries studied it was found that in the coronary arteries and in the circle of Willis, the severe plaque and the fibrous plaque played the most important roles, respectively. Graphic representation can make differentiation between HAG and LAG easy.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Arteriosclerose/patologia , Arteriosclerose/classificação , Vasos Coronários/patologia , HumanosRESUMO
UNLABELLED: To study the atherosclerotic lesion (a.l.) in the two aorta segments (thoracic and abdominal) in a given set of autopsies (total 2043) performed during five years (1981-85) in one of the principal general hospitals in the city of Havana, a set of five variables was used as part of a new biometric system (BS), to characterize the a.l. in any vascular sector. Three of these variables represent the main types of a.l., fatty streaks (X), fibrous plaques (Y) and severe (complicated and calcified) plaques (Z), while the others were indices of stenosis (P) and benignity (B). Classical dissection and pathological laboratory procedures were performed. Qualitative and quantitative gross morphometric analyses were done by a digitilizer joined to a NEC (9801) personal microcomputer (Japan). These data were processed in a medium size computer EC-1040 (GDR). The multivariate statistical techniques, the principal component analysis (PCA) and the discriminant analysis (DA), were used applying the "SPSS" programme. CONCLUSIONS: (1) PCA revealed in the two aorta segments studied a first component of benignity, fatty streaks (X) and benignity index (B) and a second component of severity, severe plaques (Z) and stenosis number (P). Because of the dimensions of the two aorta segments (width and length) the dominant, first component, is benignity. So the BS is useful in characterizing and describing the lesional state of any aorta segments; (2) DA and BS proved to be useful to distinguish between the high atherosclerotic group (HAG) and the low atherosclerotic group (LAG). The correct classification rate exceed in all cases 70%. The three components of the lesional state vector (X,Y,Z) distinguish the groups. The stenosis (P) and benignity (B) indices proved to be most relevant. The sign of benignity index is always the same as that of the LAG. Thus this variable truly represents benignity. The coherence and consistency of the BS was also proved by DA.