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

Sustained progression and loss of the gender-related difference in atherosclerosis in the very old: A pathological study of 1074 consecutive autopsy cases

INTRODUCTION

Epidemiological surveys show decrease or reversal of male predominance in cardiovascular mortality in the very old, but the actual condition of atherosclerosis in the very old is largely unknown. The objective of this paper is to reveal whether the atherosclerosis continues to progress, or the gender-related difference exists in the very old.

METHODS

The subjects were 1074 consecutive autopsy cases of in-hospital death. The male:female ratio was 1.1:1 and the average age was 80 years. Macroscopic evaluation was performed on the degree of atherosclerosis in 10 arteries including the intracranial arteries, carotid artery, aorta, coronary artery, and femoral artery.

RESULTS

The severity of atherosclerosis differed greatly among arteries. The age-related increase of the atherosclerotic degree was evident, even after 80 years of age. The atherosclerosis was more severe in males than in females in their 60s, but this male predominance decreased with ageing and finally disappeared in their 90s.

CONCLUSION

The sustained progression of atherosclerosis and loss of the gender-related difference probably account for the increase of cardiovascular mortality in very old females. They also suggest that the prevention of the atherosclerotic progression is still important in the seventh and eighth decade of life.

Cardiovascular risk factors and hyalinization of renal arterioles at autopsy. The Honolulu Heart Program

Nephrosclerosis, commonly found in subjects with hypertension and diabetes, is marked by hyalinization of arterioles and fibroplasia of small arteries in the renal cortex. Cardiovascular risk factors that predicted subsequent hyalinization of renal arterioles at autopsy were identified, using data from the Honolulu Heart Program, a prospective epidemiological study of cardiovascular disease (CVD) in Japanese-American men. Among 8006 participants at baseline, 1381 died between 1965 and 1982; 285 of these had a protocol autopsy, and 150 had assessments of arteriolar hyalinization from renal tissue. Subjects were categorized into four groups on the basis of the number of hyalinized arterioles per square centimeter of renal tissue, and CVD risk factor levels and proportions were compared across these groups with the use of general linear models and logistic regression. Multivariate assessment using logistic regression demonstrated that diastolic blood pressure (DBP) and glucose level were positively associated and alcohol intake was negatively associated with an elevated degree of renal arteriolar hyalinization, independent of other CVD risk factors. The odds ratios for elevated hyalinization associated with a 10-mm Hg increase in DBP, a 20-mg/dL increase in glucose level, and a 30-mL/d increase in alcohol intake were 1.97 (95% confidence interval [CI] = 1.24-3.12), 1.23 (95% CI = 1.07-1.41), and 0.24 (95% CI = 0.11-0.55), respectively. Associations were similar when prevalent cases of CVD were excluded and when autopsy selection bias was taken into account. Renal arteriolar hyalinization was also more strongly associated with atherosclerosis in the larger cerebral vessels (Spearman's r = .59, P < .001) than in the coronary arteries (r = .16, P = .073) and aorta (r = .24, P = .022). Hyalinization was significantly related to cardiovascular-renal mortality, and this association was accounted for by other CVD risk factors. These findings suggest that blood pressure, glucose level, and alcohol intake are independent predictors of hyalinization in renal arterioles and that this type of renal vasculopathy may be a marker for atherosclerosis in other vascular regions, particularly the cerebral vessels. The protective association involving alcohol and the possibility that renal arteriolar hyalinization may be an indicator of cerebral atherosclerosis may warrant investigation in other populations.

Predictors of myocardial lesions in men with minimal coronary atherosclerosis at autopsy. The Honolulu heart program

Some cardiovascular risk factors are associated with clinical coronary heart disease but not with autopsy evidence of coronary atherosclerosis. To determine whether these risk factors might operate through mechanisms other than atherosclerosis, we examined associations between cardiovascular risk factors and subsequent intramural myocardial lesions assessed by protocol autopsy between 1965 and 1984 in 120 Japanese-American men from the Honolulu Heart Program who had minimal coronary atherosclerosis (American Heart Association (AHA) panel score < 3 on scale of 1 to 7). Age-adjusted prevalence of myocardial lesions was related to smoking status (P < 0.01), as well as amount, duration, and pack-years of smoking (P < 0.03). In a multiple logistic model, smoking (20 pack-years) was directly associated and fish intake (> or = 2 times/wk) was inversely associated with myocardial lesions independently of age, cholesterol, systolic blood pressure, body mass index, alcohol, diabetes, total calories, and animal protein intake (odds ratio (OR) = 1.5, 95% confidence intervals (CI) = 1.1 to 2.0 and OR = 0.35, 95% CI = 0.2 to 0.9, respectively). The protective effect of fish intake was most evident among men who did not have hypertension at baseline. Indices of obesity, body fat distribution, and physical activity and levels of triglyceride and alcohol intake were not associated with myocardial lesions. Thus, the adverse effects of smoking and the protective effects of fish consumption may extend to individuals relatively free of coronary atherosclerosis, possibly through hemostatic mechanisms or effects on small intramural arteries.

Serum lipids and lipoproteins as predictors of atherosclerosis. An autopsy study

A prospective study of autopsy-determined measures of atherosclerosis in aortas and coronary and cerebral arteries was completed for a group of 83 men who were free of clinical cardiovascular disease and cancer when they entered the Cooperative Lipoprotein Phenotyping Study in 1970. Total cholesterol minus high density lipoprotein cholesterol (HDL-C) was significantly associated with measures of atherosclerosis in all three groups of vessels. The patterns of associations for total, low density lipoprotein, and very low density lipoprotein cholesterol were similar but generally weaker and not significant for atherosclerosis in the cerebral arteries. Inverse associations of HDL-C with atherosclerosis in the circle of Willis and aorta were significant, but those for the coronary arteries were not. These associations were independent of other major risk factors for atherosclerosis in multivariate analyses. Similarities between these findings and those for clinical cardiovascular disease in the same cohort indicate that the opposing patterns of increased risk of clinical cardiovascular disease associated with total cholesterol and the decreased risk associated with HDL-C also exists at the level of atherosclerosis in a variety of arteries.

Postmortem findings in sudden and non-sudden deaths among Japanese-American men in Hawaii

Analyses were made of the cause of death and major pathologic findings among 1,085 autopsied Japanese-American men in Hawaii to determine the differences between the 167 men who experienced sudden death within 24 hours of being well and the 918 men with non-sudden death. Sudden deaths were further divided into three subgroups according to the interval from the onset of symptoms to death: (less than one hour; one to six hours; more than six hours). Nearly 90 percent of sudden deaths and 25 percent of non-sudden deaths were attributed to cardiovascular disease. The proportion of deaths due to coronary heart disease was highest in sudden deaths less than one hour (72 percent) and lowest in sudden deaths more than six hours (49 percent), whereas the proportion of stroke deaths was highest in sudden deaths more than six hours (37 percent) and lowest in sudden deaths less than one hour (9 percent). The prevalence of myocardial infarction and the grade of coronary atherosclerosis were also significantly greater for sudden deaths (especially sudden deaths less than one hour) than for non-sudden deaths.

Morphometric quantification of atherosclerotic plaques by computer-assisted image-analysis of histographs

A method is described for quantifying the amount of atherosclerotic plaque in collapsible blood vessels by a computer-assisted image analysis of cross-sectional contours traced under microscopic visualization. The digitized contours are processed using a computer program that transforms the irregular image of the collapsed vessel into an ideal geometry and then calculates in vivo linear and areal parameters, variables, and ratios. The analysis is based on conventional stereologic principles and utilizes relatively inexpensive and widely available equipment: microscope with drawing tube attachment, digitizing board, microcomputer, monitor, and printer or plotter. Some of the output data include the fraction of vessel lumen occluded by plaque, average thickness of plaque, the fraction of wall surface area covered by plaque, and the ratio of the vessel bore to vessel wall volumes. The error and precision of measuring lumen occlusion and plaque surface area are assessed.

Adenomatous polyps and atherosclerosis: an autopsy study of Japanese men in Hawaii

It is generally accepted that most colorectal cancers arise from adenomatous polyps and most coronary heart disease is caused by severe atherosclerosis. In order to compare the frequency of these disease precursors in men of Japanese ancestry in Hawaii, the degree of atherosclerosis of the aorta and coronary arteries was estimated by the panel method in 288 male autopsy subjects. The extent of atherosclerosis was then compared in men who did or did not have adenomatous polyps as determined at autopsy. The degree of atherosclerosis of the coronary arteries and aorta was positively and significantly related not only to the presence of adenomatous polyps, but to their size, multiplicity, and degree of atypia as well. This study suggests that shared environmental events could account for the development of severe atherosclerosis and adenomatous polyps. At the same time, it has been observed that hawaii Japanese men experience colon and rectal cancer rates higher than those of US Whites, but their coronary heart disease (CHD) rates are intermediate between the low rates of Japan and the high rates of the US white population. These differences in disease trends and differences in the serum cholesterol and fat intake of Hawaii Japanese men with CHD and colon cancer have suggested that men with these diseases represent different subsets of the westernized Japanese population. If CHD and colon cancer occur in different subsets of this population, they must stem from the accumulation of other risk factors superimposed upon the initiators of their precursor lesions.

Pulmonary megakaryocytes: "missing link" between cardiovascular and respiratory disease?

Pulmonary megakaryocytes were quantitated in a series of 30 consecutive hospital necropsies using a two stage immunoperoxidase stain for factor VIII related antigen. In all 30 cases they were found with a mean density of 14.65 megakaryocytes/cm2 in lung sections of 5 micron in thickness. The maximum concentration of intrapulmonary megakaryocytes was consistently found to be in the central zone of the right upper lobe. Less than 22% of the observed cells possessed abundant cytoplasm, the rest appearing as effete, naked, and seminaked nuclei. The mean megakaryocyte count was found to be increased in association with both respiratory pathology (positive smoking history and impaired lung function) and cardiovascular disease states--shock; thromboembolism; myocardial infarction; and severe atheroma in the abdominal aorta, the coronary circulation, and the circle of Willis. Pulmonary megakaryocytes probably embolise from bone marrow. This may reflect stimulated thrombopoiesis, caused by increased platelet consumption in association with atherosclerotic disease, but it cannot be taken to confirm that the lung is the principal site of platelet production.

The surface measurement of aortic atherosclerosis: critical survey and comparison with histologic findings

Both the reproducibility of the surface measurements of aortic atherosclerosis and the agreement between gross inspective and histologic changes were evaluated. Aortas from male broad breasted white turkeys were chosen because of the high incidence of spontaneous and typical atherosclerotic lesions in this animal strain. Ten male turkeys were killed at 33 weeks of age. The aortas were removed including the iliac bifurcation and stained with Sudan III. Each aorta was processed blindly by four pathologists and a computerized planimeter to determine normal areas, sudanophilic areas and areas covered by plaques. The analysis of variance showed significant differences among the four pathologists' measurements of sudanophilic areas (P less than 0.01) and areas covered by plaques (P less than 0.001). The coefficients of variation among the four determinations made by one pathologist on the same aorta were 3.6% for total aortic area; 10.08% for sudanophilic area; 47.6% for the area covered by plaques. On each aorta histology was performed at the level where all the four pathologists recorded the same findings at inspection, namely a normal area, a sudanophilic area, and an area covered by plaques. Important discrepancies occurred between findings at inspection and those of histologic examination: the ten areas classified as "normal" by all the four pathologists at inspection were shown at histologic examination to be normal in only two cases. In one case a musculo-elastic layer and in seven cases a fibro-elastic layer were found. The ten areas classified as "sudanophilic" by all the observers showed a fibro-elastic layer in five cases, a musculo-elastic layer in two cases and normal findings in three cases. The ten areas classified as "covered by plaques" displayed a typical atherosclerotic plaque in all cases but one. In conclusion, our data indicate that the reproducibility of gross inspective methods is low. Important discrepancies exist between findings at inspection and histologic examinations. The relevance of these findings remains to be established as far as the assessment of human atherosclerosis is concerned.

Identification of potential antiatherosclerotic/hypolipidemic agents by their effect on hepatic conversion of androst-4-ene-3,17-dione to etiocholanolone and androsterone

Clinical observations have shown that hypercholesterolemia is associated with abnormal androgen metabolism, viz. an increased excretion of etiocholanolone (E) relative to androsterone (A). Substances which restore the A/E ratio to normal likewise lower serum cholesterol. Postulating that the abnormal steroid and sterol metabolism may be either causally related or dependent on the same metabolic defect, we have developed in vitro and in vivo models to select drugs which favorably effect the ratio of A to E produced from [4-14C]androst-4-ene-3,17-dione [4-14C]A-dione). The in vitro model employs a mixture of rat liver microsomal delta 4-3-ketosteroid-5 alpha-reductase and cytosolic 3 alpha-hydroxysteroid dehydrogenase and delta 4-3-ketosteroid-5 beta-reductase. Kinetic and mechanistic studies have been performed on active compounds using this in vitro assay. The in vivo model employs i.v. injection of [4-14C]A-dione followed by collection of bile in anesthetized, hypophysectomized female rats. Many compounds preselected in the in vitro assay likewise reduced the A/E ratio in vivo. One of these compounds (CGS 10614A) also lowered serum cholesterol and reduced the incidence and severity of atherosclerotic lesions in aortas of cholesterol-fed rabbits.

A computerized scanner to quantify atherosclerosis

A method is described for the quantitation of atherosclerotic lesion after excision and staining of the vessel. Essentially the device consists of a microscope with a computer-controlled stage which moves a photographic negative image over a square beam (o.1 mm sides) of light. At each translation-step of the stage a transmittance reading is taken using a photomultiplier tube for detection. The computer stores topographical values (typically around 6,000) and, by setting a threshold, can determine the fractional area of artery which is diseased.

Diet-induced atherosclerosis and experimental hypertension in stumptail macaques (Macaca arctoides). Effects of antihypertensive drugs and a non-atherogenic diet in the evolution of lesions

This study was carried out to determine the evolution of atherosclerotic lesions during a therapeutic period during which regression might be appreciated. We produced aortic and coronary atherosclerosis in 27 young adult stumptail macaques (Macaca arctoides) by feeding a diet supplemented with 2% cholesterol and 25% fat. Hypertension was produced by bilateral or unilateral narrowing of the renal artery. After six months of this regimen, four monkeys were killed (group 1) and 23 monkeys were divided into three groups: group 2 received unsupplemented diet; group 3 received the same diet as group 2 and drug treatment for hypertension; group 4 was continued on the atherogenic diet and received antihypertensive drug treatment. The results indicate that deleting the atherogenic diet leads to a decrease in the lipid content of the lesions and a transformation of the lipid laden atherosclerotic plaques into lipid-poor, fibro-collagenous lesions, with a decrease in the amount of coronary luminal narrowing. Partial control of systolic hypertension by antihypertensive drugs did not accelerate the involution of the atherosclerotic lesions over the relatively short period of this study. No statistically significant correlation by regression analysis was observed between the level of blood pressure elevation, the plasma renin activity, or the degree of the drug response, and the severity and extent of the atherosclerotic lesions. Furthermore, severe arterial hypertension without an atherogenic diet (group 5) produced arteriosclerosis of the aorta, and intensified branch cushions in the coronary arteries, without inducing lipid deposition in either vascular bed.

A xerographic method for the quantitative assessment of atherosclerotic lesions

A new method has been developed for the quantitative assessment of atherosclerotic lesions, in which a conventional xerox machine is the sole equipment used. As an example, the aorta from a cholesterol-fed rabbit was removed in toto, opened longitudinally along its anterior margin, flattened in a transparent polypropylene bag and then xeroxed. The outlines of the atherosclerotic lesions were traced on translucent graph paper ruled into 1 mm squares. The squares within those outlines were counted and expressed as a percentage of the whole surface. This xerographic method is rapid and reproducible and is achieved without changing the magnification; it gives comparable or better results than other staining methods. As the aortic specimen is undamaged by fixation or staining, the specimen can be used for subsequent morphological or biochemical studies. Thus, the degree of surface involvement can be correlated with other morphological or biochemical changes in the same arterial samples.

Consensus opinion and observer accuracy in electrocardiography with reference to coronary arteriographic information

In this study reader performance in resting electrocardiographic (ECG) reading and case summary interpretation was investigated. Eight cardiologists were asked to read independently 105 paired ECG--Case summary sheets on either two or four occasions. The order of ECG--Case summary inspection for each sheet was randomized over trials. The results show low levels of inter- and intra-reader reliability when physicians report on ECG traces. Reference to coronary arteriographic information confirms that the resting ECG has limited utility in the detection of coronary artery disease.