Pathobiological determinants of atherosclerosis in youth (PBDAY Study), 1986-96.

This article is a summary of the 10-year multinational collaborative WHO/ISFC Study of Pathobiological Determinants of Atherosclerosis in Youth (PBDAY Study). Details are provided of the study design, relevant results, conclusions, and recommendations, as formulated at a consultation of the heads of PBDAY Reference Centres, held in Budapest, Hungary, in October 1996. The WHO/ISFC study provides unique information about the determinants of atherosclerosis and structural changes in the arteries, especially during their early stages, and their progression from early life in populations with vastly different lifestyles. The pilot study covered subjects aged 5-34 years, of both sexes, from 18 centres in 15 countries, while the main study covered 11 centres in 11 countries. Included were both developed and developing countries with different economic, sociocultural and nutritional patterns from five WHO regions. Collected was background epidemiological information, information about cases, and special studies of arteries using various morphometric methods and specialized techniques. Atherosclerotic lesions start to develop early in life independently of race, sex or geographical origin. The rate of fatty streak development is higher between 15 and 25 years of age, while raised lesions begin developing slowly during the second decade of life, progressing steadily during the third and more rapidly during the fourth. Fatty streaks are more prevalent among females and raised lesions among males. The prevalence and extent of raised lesions were greater in countries with a high prevalence of known risk factors and high mortality rates for cardiovascular diseases, coronary heart disease, and cerebrovascular diseases.

Pathomorphometrical characteristics of atherosclerosis in youth. A multinational investigation of WHO/World Heart Federation (1986-1996), using atherometric system.

BACKGROUND AND AIM: From 1986 to 1996, 1339 autopsies were performed on children and young adults, aged 5-34 years, in 18 countries of five continents in the course of the multinational investigation of the World Health Organization/International Society and Federation Cardiology (WHO/ISFC), "Pathobiological Determinants of Atherosclerosis in Youth" (PBDAY). A set of 966 left-half thoracic and 947 left-half abdominal aortae and 958 right coronary arteries were processed in the Center of Investigations and References of Atherosclerosis of Havana (CIRAH), i.e., one of the Reference Centers of the PBDAY. Pathomorphological and morphometrical analyses were carried out by a well-established method, the Atherometric System (AS). METHODS AND RESULTS: By qualitative analysis AS permitted the identification of each type of atherosclerotic lesions (AL). The quantitative analysis, using a digitizer (MYPAC-Japan, a PC-Pentium 200 Mhz-32 MB RAM), and the software Atherosoft, allowed the measurement of the intima surface occupied by any kind of AL, and estimation of the volume occupied and thus the degree of obstruction and stenosis of the lumen. The autopsy data were divided into three age groups: a) 5 to 14 years; b) 15 to 24 years and c) 25 to 34 and processed by age and sex. The commercial package NCSS was utilized for statistical analysis of the data. CONCLUSIONS: Of particular interest were the following findings: a) Atherosclerosis increases with age; b) Fatty streaks (FS) were always present already at 5 years of age, independent of the country, climate, state of nourishment, type and amount of foods and the habits and lifestyle of the population studied. FS progressed most rapidly from 15 to 24 years. The fibrous plaque began to appear slowly at the end of the second and rapidly progressed after the third decades. The severe plaque was rarely observed before 30 years of age; it appeared in the fourth decade and then progressed slowly, but steadily.

Atherosclerotic lesions, myocardial damage and lipidograms: a multiarterial study applying an atherometric system and canonical correlation.

472 autopsy subjects were examined with the following aims: to study the association pattern of atherosclerotic lesions between different arterial sectors, the impact of serum lipid disorders (total cholesterol, HDL-c, LDL-c, VLDL-c, and triglycerides were analyzed) and the association pattern between the atherosclerotic lesions in different arterial sectors and the degree of heart damage. For morphometric analysis of the vessels (aorta, circle of Willis, coronary, renal, iliac, and femoral arteris) the atherometric system was used. The most relevant results were as follows: the lipid disorders show their greatest impact in the heart, coronary and femoral arteries and abdominal aorta, whereas the strongest correlations between the atherosclerotic lesions in different arterial sectors were found in those with anatomical continuity.

Coronary atherosclerosis and chemical trace elements in the hair. A canonical correlation study of autopsy subjects, using an atherometric system and the X-ray fluorescence analysis.

An atherometric system (AS) was used to study coronary atherosclerotic lesions of a sample of 73 autopsy subjects. The content of nine chemical elements in the hair (K, Ca, Zn, Br, Sr, Pb, S, Cl, Cu) and the rates Zn/Cu and Ca/K were determined by energy dispersive X-ray fluorescence (EDXRF) analysis. Some canonical correlation analyses (CCA) were made of different combinations of chemical elements contents and of the following descriptive arterial variables of As: fatty streaks, fibrous plaques, severe (complicated plus calcified), plaques, and total atherosclerosis and the three weighted indices of AS, i.e. obstruction, stenosis and benignity. The arterial variables were obtained from the three major epicardial branches of the coronary arteries. Similar CCA analyses were performed to correlate chemical elements of the hair with some heart variables of AS, such as heart weight and estimated total volume of myocardium damaged by fibrosis and/or necrosis. The most remarkable results were as follows: Combinations of Pb, Ca/K, Zn/Cu and Fe, Ca/K, Zn/Cu were always strongly correlated with fatty streaks, fibrous plaques and severe plaques of the three coronary artery branches and the total coronary artery system, with the only exception of the left circumflex coronary artery when Fe was included. Similar results were recorded from obstruction, stenosis and benignity indices of AS. These two combinations of chemical elements were also correlated with the heart variables of AS. When the group of elements was integrated by Br, Ca/K, Zn/Cu, there were significant results with the heart variables, but not with the arterial variables of the AS.

Neurohistochemical and electron microscopic investigations of pathological and age-related changes in the cardiovascular system.

Neurohistochemical and electron microscopic investigations of the autonomic nervous system (ANS) of man and animals suggest that its ontogenesis can be divided into the premediatory, mediatory and postmediatory periods of development. The postmediatory period begins heterochronically in various ganglia of the ANS. A normal process of early cardiac desympathization usually occurs at the age of 35 to 60 years. Specific changes of preceding sudden cardiac death are elicited in different parts of the ANS and adrenal glands. This is accompanied by focal myocardial desympathization. Coronary vessels and conducting system which may influence myocardial hypersensitivity zones to catecholamines are involved in the process of destabilization of the cardiac function. Moreover, relationships are demonstrated which exist between the atherosclerotic lesions of the aortic wall and the status of its nerve plexuses.

Coronary atherosclerosis and hair elements contents. A correlation study of 102 autopsy subjects using the energy dispersive X-ray fluorescence analysis and applying an atherometric system.

An atherometric system (AS) was used to study the coronary atherosclerotic lesions of a consecutive series of 102 autopsies divided into two groups according to the principal cause of death, the myocardial infarction and the low atherosclerosis groups, respectively (MIG 67 cases, LAG 35 cases). The hair elements contents (K, Ca, Zn, Br, Sr, Pb, S, Cl, Cu, and their rates Ca/Sr, Zn/Cu and Ca/K) were determined by energy dispersive X-ray fluorescence (EDXRF) analysis. A PEARSON correlation analysis was done between each element and the following descriptive arterial variables of the AS: fatty streaks (X), fibrous plaques (Y), severe (complicated plus calcified) plaques (Z) and total atherosclerosis (sigma) and the three weighted indices of the AS: obstruction (omega), stenosis (P) and benignity (B). These variables were obtained from the three major epicardial branches of the coronary arteries (right RC, left anterior descending LAD and left circumflex LC). From a total of 189 possible correlations between the 9 elements and their 3 combinations and the 7 variables of the AS in the three coronary arteries, 86 (45.5%) were significant. The fatty streak was the best correlated variable. It correlated with all elements with the only exception of chloride. The fibrous plaque was poorly correlated. The severe plaques and total atherosclerosis correlated mainly with Zn and Pb in the MIG and Sr in the LAG. The weighted indices have the same behaviour. Also some correlations were found between K, Ca, Zn, Br, Sr, Pb, Ca/Sr, Zn/Cu and Ca/K ratios with some of the variables of the AS in each coronary artery.

Atherosclerotic lesion of the circle of Willis: its study applying an atherometric system using multivariate statistical techniques.

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.

Atherometric system. A suitable methodology to characterize atherosclerotic lesions in any artery or group of patients.

The atherometric system (AS) is a set of methods and procedures derived from a group of interdependent and strongly interrelated variables, resulting from certain biophysical (rheological, geometrical, hemodynamic) and mathematical considerations and reasonings. The variables of the AS are divided into two groups: the arterial and the organ-related variables. Each of them is subdivided into (a) descriptive variables, since correct use of them and their different combinations will enable proper examination of all pathomorphological and pathophysiological alterations to arteries and to atherosclerotically affected organs and (b) weighting indices which yield accurate prediction of the atherosclerotic process, its severity and consequences. The AS is a tool for medical and biological investigations in relation with any vascular disease due to atherosclerosis. It is useful for etiological, pathogenetical, pathomorphological, morphometrical, pathophysiological, biochemical, and epidemiological studies. Also it has proved its facilities for experimental studies with a view to elucidating possible effects of therapeutic action and effectiveness of pharmaceuticals to which anti-atherogenetic or anti-atherosclerotic activities are attributed.

Atherosclerosis in diabetes and hypertension. A comparative morphometric study of their progression using an atherometric system.

The three major epicardial coronary arteries of a set of 472 autopsy cases divided into four groups: a) non-diabetics and non-hypertensive, 322 subjects; b) hypertensive, 75 subjects; c) diabetics, 57 subjects and d) hypertensive and diabetic, 17 subjects, were studied. Classical pathomorphological procedures and an atherometric system (AS), suitable to characterize the atherosclerotic lesions, was used searching for differences between the level of atherosclerosis into these four groups and its eventual progression according to the time of evolution of these diseases. Raw data processing was full automated and some univariate and multivariate statistical procedures (means, standard deviations, ANOVA, MANOVA and principal components analysis) were performed using two commercial statistical packages: "NCSS" and "SYSTAT". The most remarkable findings were the following: Diabetes and hypertension have both strong impact upon the rate at which the atherosclerotic process takes place in subjects affected by these diseases. The time of evolution of both diseases correlates positively and independently of age with the velocity of the atherosclerotic process at the three coronary arteries. The impact of diabetes seems to be stronger and is particularly expressed by the severe plaques (Z) while the effect of hypertension is specially observable at the fibrous plaques (Y). There seems to be no significant interaction (synergism) between the two risk factors upon the measurement of the atherosclerotic lesions, that is, they have an additive effect. Two simple underlying factors can be used to account for interindividual differences. These two factors are "dominated", respectively, by fibrous (Y) and severe plaques (Z).

Morphometric, histochemical and autoradiographic studies on myocardial cells in experimental cardiac hypertrophy and ischemia.

Experimental studies were conducted into 170 adult male Wistar rats for the purpose of analysis of cellular adaptation processes of the myocardium to acute ischemia. One group of the animals were exposed to physical endurance training, i.e. 180 h of swimming exercises, up to 3 h daily. Positive verification of cardiac hypertrophy was considered a measure of accomplished cellular adaptation. Training-induced increase of relative and absolute heart weight was 25 and 30%, respectively. Acute myocardial ischemia had been produced by ligature of the left coronary artery. There were no significant differences between trained and untrained animals for incidence and size of infarction and postoperative lethality, while cardiac decompensation was less often recorded from trained animals. To study cellular adaptation as well as differences between trained and untrained animals, tissue samples were taken from the non-ischemic part of the left ventricle and checked by means of histology, electron microscopy, morphometry, quantitative histochemistry, and histo-autoradiography 1, 2, 4, 7, and 14 days after occlusion of the coronary artery. The studies have shown endurance training to result in unambiguous modification of structural as well as functional response of the nonischemic heart. Included in such structural modification at cellular level are significant changes in mitochondrial membranes, sarcoplasmic reticulum, and T-system. Structural modification was reflected in changes to the oxidative enzymes and DNA metabolism. Different patterns of cellular reaction could be positively verified up to 14 days after myocardial infarction.

Histopathological sinus node classification and its relation to coronary atherosclerosis using an atherometric system.

Studies were conducted into 100 consecutive subjects (autopsy material), 53 men and 43 women between 31 and 70 years old, who had died a natural death. The HUDSON-procedure was used for histopathological analysis of the cardiac conducting system (CCS). About 48 microscopic slides of each subject, including sinus node (SN) tissue, were inspected by 4 pathologists in a blind study. The findings were classified by 3 different groups according to histopathological data of the SN, viz. changes and distribution of P and T cells, stroma, artery, and innervation of SN. The 3 major epicardial branches of coronary arteries were prepared for morphometric studies by WHO standards. A digitizer coupled to a microcomputer LTEL (Cuba, IBM-compatible) was used for quantitative evaluation of atherosclerotic lesions (AL), and all data were subsequently processed on the same computer, using a statistical commercial package (Number Cruncher Statistical System) for results. An atherometric system was used and proved to be a properly standardized methodology, suitable to characterize AL in any vascular sector or group of patients. The most remarkable results were as follows: Three-group classification was useful in estimating the association between pathomorphological data of SN and coronary atherosclerosis. The atherometric system proved to be a powerful tool to study and characterize atherosclerotic lesions in coronary arteries.

[The atherometric system]. / Aterometricheskaia sistema.

Atherometric system designed for the evaluation of the atherosclerotic changes in the individual arteries and alterations in the organs affected is described. The system includes two groups of functions--arterial and organ-dependent. Using these interrelated functions and biophysical and mathematical methods it becomes possible to estimate quantitatively pathomorphological and pathophysiological changes in the arteries and organs supplied by them.

Coronary atherosclerosis in sudden death: a comparative study applying an atherometric system.

Coronary arteries affected by atherosclerosis and its myocardial related damage in cardiac and non-cardiac sudden death subjects (152 and 98, respectively) including a low atherosclerosis group (250 subjects) were studied in autopsy material applying a new well standardized atherometric system. A high statistical significance of all variables of this system was found between the groups studied.

Atherometric system: morphometric standardized methodology to study atherosclerosis and its consequences.

A group of strong mutual dependent variables, obtained by measuring some morphological and pathomorphological characteristics of an artery affected by atherosclerosis (arterial variables) and its organ-related damage (organ-related variables DRV), yield a suitable methodology to study and characterize this disease and its further severe consequences. Applying some biophysical (rheological, geometrical, and haemodynamical) and mathematical reasonings to those measurements an atherometric system AS is derived. It is a new standardized morphometric methodology which allows, by the use of their variables, the development of useful pathomorphological, pathogenetical, statistical, and epidemiological investigations. The variables of the AS are divided into 1. descriptives and 2. weighting indices WI to estimate the severity of atherosclerosis. The descriptive arterial variables were obtained from each type of atherosclerotic lesion AL, fatty streak, fibrous plaque, and severe (complicated and calcified) plaques, latter normalize and further represented in a 3-dimensional vector, in order to conserve all the analytical information of each type of AL. Their WI are obstruction, stenosis, and benignity. The descriptives DRV (estimated volumes) and their respectively derived WI, are in relation with the pathological conditions: fibrosis, necrosis, haemorrhage, total damage, and their counterpart non-affected (sufficient) variables. A digitizer coupled to a personal computer LTEL (Cuba) to obtain the primary data was used. All data were processed in a computer EC-1040 (G.D.R.) using the statistical commercial package "SPSS" for scientific analysis.

The conduction system in dilated cardiomyopathy. A pathomorphological study.

A semi-serial histopathological study was conducted into the cardiac conduction system (CCS) of 14 autopsy subjects with dilated idiopathic cardiomyopathy (DIC). Clinical and pathomorphological data corresponding to this disease were compiled by Hudson's criteria. The most important histopathological findings were the frequency of vascular changes observed in small-size arteries that irrigate the sino-atrial and atrioventricular nodes, the bundle of His, the origin of both bundle branches, and the upper portion of the ventricular septum. Vascular changes, although unequal and inconstant, together with regressive and inflammatory features were observed in the majority of specimens. Also, good correlations were found to exist between electrocardiographic data and the direct cause of death, the intensity and/or extension of lesions did not correlate with the duration of the disease. While the vascular lesions might have been the first pathological changes, their variability and inconsistency suggested that more than one aetiological factors were involved in this type of cardiomyopathy.

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.

Atherosclerotic lesion of the aorta: its study applying a biometric system using multivariate statistical techniques.

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.