The epidemiology of coronary heart disease. A review

Diversity in citations to a single study: A citation context network analysis of how evidence from a prospective cohort study was cited

Between its origin in the 1950s and its endorsement by a consensus conference in 1984, the diet–heart hypothesis was the subject of intense controversy. Paul et al. (1963) is a highly cited prospective cohort study that reported findings inconvenient for this hypothesis, reporting no association between diet and heart disease; however, many other findings were also reported. By citation context and network analysis of 343 citing papers, I show how Paul et al. was cited in the 20 years after its publication. Generally, different findings were cited by different communities focusing on different risk factors; these communities were established by either research foci title terms or via cluster membership as established via modularity maximization. The most frequently cited findings were the significant associations between heart disease and serum cholesterol (n = 85), blood pressure (n = 57), and coffee consumption (n = 54). The lack of association between diet and heart disease was cited in just 41 papers. Yet, no single empirical finding was referred to in more than 25% of the citing papers. This raises questions about the value of inferring impact from citation counts alone and raises problems for studies using such counts to measure citation bias.

Heart Disease

There has been a continuing debate among health professionals concerning the appropriate strategy of use for the prevention of ischemic heart disease: a targeted high-risk group strategy or a community strategy. A careful review of the evidence demonstrates that neither approach can be recommended to the exclusion of the other. The results are, however, supportive of the lowering of serum cholesterol in high risk individuals. The inconclusiveness of these studies appears to be related to several problems, which are discussed in the text: statistical powerproblems, characteristics of the interventions, unique design problems associated with prevention trials, and problems related to the choice of modelsfor investigation and intervention. Several suggestionsforfuture research to address each of these problems are made.

Association between smoking habits and the first-time appearance of atrial fibrillation in Japanese patients: Evidence from the Shinken Database

BACKGROUND

We previously reported a cross-sectional analysis regarding the relationship between smoking and atrial fibrillation (AF) in a single hospital-based cohort with Japanese patients, but the effect of cessation of smoking and/or total tobacco consumption were unclear.

METHODS AND RESULTS

We used data from the Shinken Database 2004-2011 (men/women, n=10,714/6803, respectively), which included all new patients attending the Cardiovascular Institute between June 2004 and March 2012. After excluding those previously diagnosed with AF (n=2296), 15,221 patients (men/women, n=9016/6205) were analyzed. During the follow-up period of 2.0±2.1 years (range 0.0-8.1), the incidence rates of new AF in smokers and non-smokers were 9.0 and 5.0 per 1000 patient-years, respectively. In adjusted models with Cox regression analysis, smokers were independently associated with new AF [hazard ratio (HR) 1.47, 95% confidence interval (CI) 1.09-2.00]. Also, current smokers (HR 1.81, 95% CI 1.17-2.79) and smokers with Brinkman index ≥800 (HR 1.69, 95% CI 1.05-2.70) were independently associated with new AF. However, in current smokers, the HRs were not different by Brinkman index (Brinkman index <800/≥800; HR 1.81/1.82, 95% CI 1.07-3.05/0.94-3.51, respectively).

CONCLUSIONS

Smoking was independently associated with the first-appearance of AF in patients in sinus rhythm, especially when the patients continued their smoking habit. However, in patients who continued smoking, difference by total tobacco consumption was not observed, suggesting the significance of cessation of smoking for preventing AF. Our data are limited because of a single hospital-based nature and a relatively short observation period.

Effects of smoking habit on the prevalence of atrial fibrillation in Japanese patients with special reference to sex differences

BACKGROUND

Tobacco smoking is a well-known risk factor for cardiovascular disease, but controversial results have been reported regarding its relationship with atrial fibrillation (AF). Moreover, no study on the relationship between smoking and AF has yet been undertaken in a Japanese context.

METHODS AND RESULTS

We used data from the Shinken Database 2004-2011 (men/women, n=10,714/6,803, respectively), which included all new patients attending the Cardiovascular Institute between June 2004 and March 2012. AF was diagnosed in 1,698 and 598 men and women, respectively. In men, smokers were more prevalent in the AF than in the non-AF group (54.5% vs. 44.7%), whereas in women the prevalence of smokers was similar between AF and non-AF groups (14.4% vs. 15.4%). This discrepancy between the sexes seems to derive from a characteristic distribution pattern of smoking habit in women. After adjustment for various cofactors, smoking was independently associated with AF (odds ratio 1.54; 95% confidence interval 1.35-1.75; P<0.001) without a significant interaction between sex categories (P=0.195).

CONCLUSIONS

Smoking was independently associated with AF without a significant interaction between sex categories among Japanese patients visiting a cardiovascular hospital. Further studies using a prospective cohort design are required to confirm a causal link between smoking and AF in Japanese patients.

Socio-medical Characteristics of Coronary Disease in Bosnia and Herzegovina and the World

INTRODUCTION

Coronary heart disease and its etiology are complex socio-medical and clinical problem in this century. World Health Organization defined coronary artery disease as acute and chronic heart ailments due to disruption of flow and myocardial blood supply. Diseases of the cardiovascular system in spite of preventable risk factors are responsible for approximately 50% of all deaths in the developed world, and this ratio is higher in developing countries.

RISK FACTORS

CORONARY HEART DISEASE RISK FACTORS CAN BE DIVIDED IN THOSE WHICH ARE NOT PREVENTABLE SUCH AS: personal and family history of cardiovascular diseases, age and gender and preventable risk factors including: high blood pressure, elevated blood cholesterol, smoking, reduced physical activity, elevated blood sugar, increased body weight, alcohol use, psychosocial factors and nutrition. There are also newly emerging risk factors which includes increased homocysteine, thrombogenic and inflammatory factors. Prevention of coronary heart disease risk factors: The concept of risk assessment factors, their reduction, initially begun in the Framingham Heart Study and refined in other models. Primary prevention relates to changing lifestyle and influencing preventable risk factors. Numerous studies and meta-analysis showed that lifestyle modification, risk reduction factors, particularly by changing diet, stopping smoking, increasing physical activity, blood pressure control can be effective in the prevention and reduction of coronary heart disease. Primary health care physicians i.e. family physicians need to take an active role in assessment of risk factors for coronary heart disease.

CONCLUSION

The data in this paper, based on the findings from other studies, suggest the importance of using a modified algorithm in order to estimates the overall risk of coronary disease in high-risk groups among the patients in the primary health care settings.

Cigarette smoking and risk of atrial fibrillation: the Rotterdam Study

BACKGROUND

Cigarette smoking is an important risk factor for cardiovascular disease, but it is unknown whether it also contributes to the risk of atrial fibrillation.

METHODS AND RESULTS

The study is part of the Rotterdam Study, a population-based cohort study among subjects aged > or =55 years. The association between cigarette smoking and the risk of atrial fibrillation was examined in 5,668 subjects without atrial fibrillation at baseline. During a median follow-up of 7.2 years, 371 cases of atrial fibrillation were identified. Relative risks (RR) were calculated with 95% CIs using the Cox proportional hazards model, adjusted for age, gender, body mass index, hypertension, systolic blood pressure, serum cholesterol level, diabetes mellitus, left ventricular hypertrophy on the electrocardiogram, prevalent and incident myocardial infarction, prevalent heart failure, and the use of pulmonary medication. After multivariate adjustment, current smokers and former smokers had increased risks of atrial fibrillation as compared to never smokers (RR 1.51, 95% CI 1.07-2.12; and RR 1.49, 95% CI 1.14-1.97, respectively). No differences were found between men and women.

CONCLUSIONS

The results of this prospective, population-based study show that current and former smoking of cigarettes are associated with increased risk of atrial fibrillation.

Hypothetical hypercholesterolaemia and atherosclerosis

Recent pathological advances in experimental and iatrogenic atherosclerosis and critical review of the epidemiology of coronary heart disease revealed fallacious data and methodological errors underlying the hypercholesterolaemia/lipid hypothesis. Misuse of risk factors, inappropriate use of surrogates and misinterpretation of data pertaining to cholesterol's role in atherogenesis necessitate greater precision in word usage and terminology, reinstitution of the statistical reference range for cholesterol and closer scientific surveillance of aetiological endeavours in medicine.

Coronary heart disease, hypercholesterolemia, and atherosclerosis. I. False premises

Lipid-rich caseous debris of advanced lesions stimulated interest in the role of cholesterol and lipids in atherosclerosis. Lipid-containing arterial lesions in cholesterol-overfed animals (cholesterolosis) and xanthomatous vascular lesions in subjects with familial hypercholesterolemia were then misrepresented as being atherosclerotic and led to the development of the hypercholesterolemic/lipid hypothesis. It is untenable that cholesterol, an essential multifunctional metabolite, is pathogenic at all blood levels and hypercholesterolemia is not prerequisite for human or experimental atherosclerosis. Serum cholesterol levels display a poor correlation with atherosclerosis at autopsy and with unreliable national coronary heart disease (CHD) mortality in each sex. Atherosclerosis topography and its iatrogenic production in humans and experimentally in herbivores by hemodynamic means both support a biomechanical causation and preclude causality by any circulating humoral factor. CHD, not a specific disease, is a nonspecific complication of many diseases including atherosclerosis and cannot be equated with coronary atherosclerosis due to differences in pathology and pathogenesis. Thus, extrapolations from CHD risk factors or correlations with fallacious vital statistics to atherosclerosis are invalid. It follows that the hypercholesterolemic/lipid hypothesis evolving from false premises, misuse of CHD, scientific misrepresentation, and fallacious data has no legitimate basis.

Epidemiological risk factors of coronary heart disease are not causal in atherosclerosis

Logic dictates that for scientific progress in atherogenesis "cause" must be the sole prequisite without which the disease cannot occur. Nor can it be assumed that statistical associations (risk factors) with coronary heart disease (CHD) are causal for atherosclerosis and extrapolations from correlations with CHD incidence to atherosclerosis are invalid. Any factor considered to play a role in atherogenesis requires pathological and experimental evidence consistent with the logic of Koch's specificity of cause and effect. Current epidemiological misuse and manipulation of cause and risk factors are contrary to the basic precepts of scientific logic and the fundamental need for precision in word usage. The term "risk factor", because of the current deeply entrenched false concept of causality has retarded medical progress and should be abandoned. Its adherents, guilty of a disservice to the tenets of their discipline, have also sullied the scientific integrity of medicine as a whole.

Hemoconcentration and stress: a review of physiological mechanisms and relevance for cardiovascular disease risk

Elevated levels of hematocrit and hemoglobin have been identified as an independent risk factor for the development of a number of diseases, including hypertension, coronary heart disease, and stroke. A growing body of evidence also indicates that elevations in hematocrit and hemoglobin are present in situations involving both physical and mental stressors. This paper reviews the evidence linking decreases in plasma volume causing hemoconcentration with hemodynamic adjustments associated with activation of the sympathetic nervous system, and the potential relevance of stress-induced hemoconcentration in triggering deleterious cardiovascular events. The importance of blood viscosity in understanding the effects of hemoconcentration is discussed, along with the need to evaluate the degree of hemoconcentration during stress for accurate interpretation of changes in certain blood constituents.

Hemostatic risk factors of coronary artery disease in the Chinese

In order to find out the hemostatic risk factors of coronary artery disease in the Chinese, antithrombin III concentration, factor VII and fibrinogen assays, plasminogen activator inhibitor-1 antigen and platelet count were determined in 51 healthy controls (mean age 63.5 years, S.D. 10.3), 55 diabetics (mean age 66.0 years, S.D. 4.8) and 56 patients with arteriographically proved coronary artery disease (mean age 63.8 years, S.D. 8.7). Of the coronary artery disease group, 19 had single vessel disease, 21 had double vessel disease and 16 had triple vessel disease. Sixteen of this group also had a past history of myocardial infarction. There was no significant difference of the hemostasis parameters between diabetics and controls. Fibrinogen and factor VII, but not plasminogen activator inhibitor, were significantly higher in coronary artery disease patients than in controls (P = 0.0001, both) and in diabetics (P = 0.0001, both). No significant difference in the parameters was found in the coronary artery disease group, whether the patients had single vessel disease, double vessel disease, or triple vessel disease, or were with or without past myocardial infarction. In the myocardial infarction group, fibrinogen and factor VII were significantly higher than in the controls (P < 0.00005 and 0.0001, respectively) and in the diabetics (P = 0.0002 and 0.0004, respectively). We suggest that increased levels of fibrinogen and factor VII, but not plasminogen activator inhibitor, would be the hemostatic risk factors of coronary artery disease in the Chinese.

Do smoking and diabetes change the hemostatic parameters?--a study in the Chinese people

Plasma plasminogen activator inhibitor-1 (PAI) antigen, fibrinogen, antithrombin III (ATIII), protein C, beta-thromboglobulin (BTG), platelet count, fibrinogen degradation product (FDP) D-dimer, factors VII and XII, as well as cholesterol, triglyceride (TG) and glucose were determined in 163 subjects. First we compared the difference of these parameters between 50 diabetics (Group D, mean age 64.9 years) and 50 age-matched healthy controls (Group C, mean age 63.1 years). Nineteen of the diabetics and 19 of the healthy controls were smokers. Plasma glucose, cholesterol, TG and protein C were significantly higher in Group D than in Group C (p = 0.0010, 0.0308, 0.0083 and 0.0068, respectively), whereas ATIII and factor XII were significantly lower in Group D (p = 0.0213 and 0.0061). Secondly, we divided 113 healthy controls (Group C, including Group C plus 63 subjects at various ages) into smokers (mean age 56.7 years) and non-smokers (mean age 40.0 years) and compared the difference between them. Fibrinogen and glucose were higher in the smokers than in the non-smokers (p = 0.0139 and 0.0402, respectively). Other parameters were not different. In conclusion, our study did not find any important hypercoagulation state in the diabetics. Smoking can only increase fibrinogen and glucose without the change of other hemostatic parameters.

The quality of epidemiological data in coronary heart disease and atherosclerosis

There are inherent difficulties in the use of indirect observations in the epidemiology of a chronic ubiquitous disease such as atherosclerosis. Such difficulties do not condone basic errors in epidemiological methodology, the use of low quality data, a lack of precision in measurements, invalid extrapolations and inappropriate use of terminology and coronary heart disease as a surrogate or synonym of coronary atherosclerosis and bias in the interpretation of data. These errors reveal a lack of rigorous and scientific standards in the epidemiology of coronary heart disease. Analysis cannot launder such data. Independent scientists must evaluate the data in respect of precision, logic and truth.

Science, atherosclerosis and the "age of unreason": a review

Research in atherosclerosis has been dominated by the lipid hypothesis. The pathology of both the cholesterol-fed animal and of familial hypercholesterolemia has been misrepresented. The vascular lesions of these disorders are not atherosclerotic but manifestations of fat storage. There has been undue faith in the epidemiology of coronary heart disease and atherosclerosis. Fundamental defects in the epidemiological approach to the cause of atherosclerosis include: (1) misuse of cause and risk factors; (2) misuse of coronary heart disease as an imprecise and inappropriate surrogate endpoint in clinical and mortality studies; (3) use of fallacious monocausal death certificates and mortality rates; (4) assumed causal role of risk factors; (5) use of fallacious dietary data; (6) ecological fallacies; (7) nonspecificity of statistical correlations and selection bias; (8) failure to take note of inconsistencies; (9) inappropriate use of the blood cholesterol level as a surrogate of atherosclerosis (substitution game) without demonstration of any such effect on arteries; and (10) misplaced faith in pathological and experimental corroborative evidence. The epidemiology of atherosclerosis is based on unscientific methodology and the lipid hypothesis as currently envisaged is invalid. There is need to review the cholesterol-lowering campaign especially for normolipidemic subjects.

Relation of serum lipoprotein lipids and apolipoproteins to obesity in children: the Bogalusa Heart Study

BACKGROUND

The relationship of serum lipoprotein lipids and apolipoproteins to obesity was studied in a biracial sample of 2,816 children of ages 5-17 in Bogalusa, Louisiana.

METHODS

Two measures of obesity were used: fatness (subscapular skinfold thickness) and fat centrality (the ratio of subscapular to triceps skinfold thickness). Plasma insulin and glucose were included as metabolic markers related to obesity.

RESULTS

The obesity associations were relatively strong with insulin (rs = 0.29, P less than 0.001, skinfold; rs = 0.15, P less than 0.001, skinfold ratio) and triglycerides (rs = 0.25, P less than 0.001, skinfold; rs = 0.19, P less than 0.001, skinfold ratio). The relationships of serum low-density lipoprotein cholesterol (LDL-C) (rs = 0.17, P less than 0.001, skinfold; rs = 0.13, P less than 0.001, skinfold ratio) and apolipoprotein (apo) B (rs = 0.16, P less than 0.001, skinfold; rs = 0.13, P less than 0.001, skinfold ratio) with the obesity measures were of lesser magnitude, but persisted after adjustment for insulin and triglycerides. The inverse association of obesity to serum high-density lipoprotein cholesterol (HDL-C) (rs = -0.13, P less than 0.001, both skinfold and skinfold ratio) and apo A-I (rs = -0.04, P = 0.03, skinfold; rs = -0.05, P = 0.004, skinfold ratio) was significant only before adjustment for insulin and serum triglycerides. Multiple linear regression of obesity measures showed that, like insulin, serum triglycerides had consistently higher standardized coefficients than LDL-C, HDL-C, apo B, and apo A-I. Apo A-I and apo B added only a small amount (less than 2%) of information to the relationship of serum lipoproteins with obesity measures.

CONCLUSION

These results indicate that serum very-low-density lipoprotein (VLDL) levels are directly and independently related to obesity. The well-known inverse association between obesity and serum HDL-C is not independent, but secondary to the elevated VLDL or triglyceride levels associated with obesity. While associations of obesity and lipoprotein cholesterol are found, far fewer occur with apolipoproteins, especially Apo A-I. Interesting race and sex differences in the relationship of obesity to serum lipoproteins and apoproteins are noted, being greater among white children and more consistent in white males.

Imprecision of the clinical diagnosis of coronary heart disease in epidemiological studies and atherogenesis

Coronary heart disease (CHD) is an imprecise diagnosis associated with a substantial diagnostic error and provides an erroneous assessment of the morbidity and mortality of myocardial ischemia and of severe coronary atherosclerosis. Due to the inability to measure the severity of atherosclerosis during life, epidemiologists frequently use the incidence of CHD as a surrogate monitor of severe atherosclerosis. It is therefore important in clinical epidemiological studies to appreciate the degree of inaccuracy of CHD statistics, which detracts from the value of such studies and their reliability.

Review of the validity of national coronary heart disease mortality rates

Epidemiologic studies of coronary heart disease are heavily dependent on national mortality rates. The diagnostic error for the coronary heart disease is substantial but unquantifiable and is conservatively at least +/- 30%. When this error is superimposed on innumerable errors and omissions in the compilation of monocausal mortality rates, the reliability of such vital statistics currently precludes their use for scientific purposes.

Basic precepts and the lipid hypothesis of atherogenesis

In approaching circumstantial evidence provided by epidemiology in support of the lipid hypothesis of atherogenesis, basic precepts include accuracy in terminology and in defining the end point to be measured. Cause must be used as the sole prerequisite without which the disease does not occur. Risk factors are not causes unless proven by other means and coronary heart disease (CHD) is an inappropriate monitor of the severity of atherosclerosis. Misuse of cause, risk factor and CHD had lead to the multifactorial concept of the etiology of atherosclerosis.

The epidemiological relationship of hypercholesterolemia, hypertension, diabetes mellitus and obesity to coronary heart disease and atherogenesis

Coronary heart disease (CHD) is an imprecise, inappropriate monitor of atherosclerosis severity and by inapplicable extrapolation CHD risk factors are incorrectly assumed to be causes of atherosclerosis. Taking into account (1) the misuse and substantial diagnostic error of CHD, (2) errors in determining the prevalence of risk factors, (3) the use of a young non-representative minority of sufferers of CHD, (4) bias posed by inclusion of familial hypercholesterolemia (FH) in clinical studies and (5) mutual inter-relationships, genetic influence and age dependence of hypercholesterolemia, hypertension, diabetes mellitus and body mass or obesity, it is unlikely that multivariate statistical analyses can adequately differentiate between their effects. These factors are age dependent and so are CHD and atherosclerosis. The importance of hypercholesterolemia in atherogenesis is suspect particularly since the vascular pathology of familial hypercholesterolemia and of cholesterol-fed animals has been misrepresented and does not provide support for the role of hypercholesterolemia in atherogenesis.

Epidemiology of coronary arterial disease in the Chinese

The occurrence of coronary arterial disease and, in particular, acute myocardial infarction in three Chinese communities, namely Hong Kong, Taiwan and China, was reviewed by using a multifaceted approach. Both the prevalence and death incidence of coronary arterial disease or acute myocardial infarction were much lower than those in most western countries: in these three places, the prevalence of coronary arterial disease, the incidence of mortality from coronary arterial disease, the incidence of acute myocardial infarction and the mortality from acute myocardial infarction were roughly one-eighth to one-quarter of the average western figures. While the prevalence and mortality figures have been declining in most affluent western countries, they have been increasing in these three large Chinese communities with 1200 million people. The implication of this increasing trend should certainly deserve more consideration in future planning in these regions. While aging is a contributing factor to such a trend, more work is required to delineate and assess the relative significance of the changes in the socioeconomic and coronary risk factors in the process of modernisation.

Risk of ischemic heart disease among primary aluminum production workers

The risk of ischemic heart disease (IHD) has been studied in relation to working conditions encountered in a primary aluminum smelter employing over 6,000 men. During the period 1975-1983, 306 new cases of IHD were identified which were matched with 575 referents. A logistic regression analysis was performed to adjust for differences in smoking habits, high blood pressure, hyperglycemia, hypercholesterolemia, and obesity. Results from this showed that white collar workers had a significantly lower risk of IHD (odds ratio 0.47, 95% confidence interval 0.31-0.70). Among blue collar workers, a significantly higher risk was observed for workers in the reduction division of the plant (OR 1.72, CI 1.09-2.97) including, in particular, Soderberg (OR 1.71, CI 1.07-2.72) and prebake (OR 2.26, CI. 1.27-4.02) potroom workers. The risk of IHD did not increase with the length of time worked in these occupations. The search for associations (among blue collar workers) of risk with nine specific contaminants (benzene soluble material, fluoride, total dust, sulfur dioxide, carbon monoxide, thermal stress, noise, physical load, and mental load) proved inconclusive, with no association reaching statistical significance.

Clustering of anthropometric parameters, glucose tolerance, and serum lipids in children with high and low beta- and pre-beta-lipoproteins. Bogalusa Heart Study

Children initially aged 21/2 to 14 years living in Bogalusa, Louisiana (n = 2530) were examined twice, 3 years apart, for fasting serum pre-beta- and beta-lipoprotein cholesterol (beta-LPC) levels. Based on averages of these levels, the children were ranked for pre-beta- and beta-LPC in combinations of extreme quintiles (low-low, high-high) or quartiles (low-high, high-low), n = 388, and were reexamined for serum lipids, lipoprotein cholesterol, glucose tolerance, and anthropometry. Skinfolds were thicker in whites than in blacks except for subscapular skinfold. Children in the high-high stratum were heavier and more obese. The postglucose insulin level was positively correlated with fasting serum triglycerides and pre-beta-LPC. Compared with other strata, high-high strata showed more clustering among half-hour and 1-hour plasma insulin, serum triglycerides and pre-beta-LPC, and trunk skinfolds. We conclude that racial differences in lipid and carbohydrate metabolism occur in all four strata, and that a strong clustering occurs more in the high-high stratum, which may, in part, explain the coincidence of several high cardiovascular risk factor levels observed in the same children. These observations document in free-living children changes of obesity, plasma glucose, and insulin metabolism related to serum lipoproteins that are involved in the early natural history of atherosclerosis.

Increased fatality and difficult diagnosis of in-hospital acute myocardial infarction: comparison to lower mortality and more easily recognized pre-hospital infarction

We studied 510 patients in the Columbia, South Carolina metropolitan area with documented acute myocardial infarction (AMI) in 1978 to investigate differences in clinical characteristics and outcome between patients who experienced AMI while inside the hospital (IN-AMI) and those who experienced AMI outside the hospital environment (EX-AMI). Mortality for IN-AMI patients (66%) was significantly higher (p less than 0.0001) than for EX-AMI patients (22%), and remained higher (p less than 0.05) even after exclusion of high-risk IN-AMI patients (surgical patients, those with serious underlying noncardiac illness, and those with underlying cardiac illness as the reason for hospital admission). Medical IN-AMI patients experienced fewer typical forms of AMI symptoms (p less than 0.05) and did not reach an intensive care unit significantly sooner than did EX-AMI patients. Time from onset of AMI symptoms to death was not significantly different between IN-AMI and EX-AMI groups (p = 0.22). Therefore AMI occurring during hospitalization was associated with poor early prognosis even after exclusion of high-risk patients. These results emphasize the need for improved approaches to prevention, identification, and management of AMI patients.

Obesity, smoking and atherosclerosis. A study of interassociations

The data gathered from male autopsied cases (25-64 years of age) in Orleans Parish have been analysed for association between measurements of athetosclerosis and measurements of obesity. The confounding effects of diseases such as hypertension and diabetes have been controlled by excluding from analysis cases known to have such diseases. The confounding effect of age and a measurement of smoking habit on the association between atherosclerosis and obesity has been controlled by the technique of multivariate regression analysis. An inverse association between smoking habit and obesity and the direct associations between smoking habit and atherosclerosis as measured by MCWT (mean coronary wall thickness), CALC (coronary calcification), RLAA (raised lesion in abdominal aorta), and RLCA (raised lesion in coronary arteries) have been confirmed. Positive though weak associations for mesasures of atherosclerosis (MCWT and RLCA) with adipose thickness have been found among whites but not among blacks. Among black cases a weak association between fatty streaks in coronary arteries and adipose thickness was found. It is suggested that obesity itself is not an atherogenic agent but that it is related to one or more atherogenic agents that affect aortas and coronary arteries differentially and that are more intensive among whites than among blacks.

An international comparison of mortality in middle-aged men from cardiovascular diseases during 1970--1974

An international comparison of mortality rates in middle-aged men (35--54 years) from cardiovascular diseases (CVD) during the period 1970--1974 was made. The material for this study was obtained from the statistics of the WHO (World Health Statist. Ann. 1970--1974, Vol. I, Vital Statistics of Causes of Death. WHO, Geneva, 1973--1976). The mean death rate of middle-aged men from all CVD and ischaemic heart diseases was clearly higher in Finland than in any other country in the world during the 5-year period. The mortality rates according to all ICD (International Classification of Diseases) main groups of diseases were determined for a selected group of countries containing all the Scandinavian countries, the United States, Canada, Hungary, Australia, Scotland, and Czechoslovakia. The death rates of all natural (ICSI-XVI) and unnatural causes (ICDXVII) were higher in Finland than in the other selected countries. Also the proportion of cardiovascular deaths as a percentage of all natural deaths was clearly higher in Finland than in any of the above countries, whereas in these countries proportionally more deaths were due to neoplasms than in Finland, especially in men aged 35--44. Only in Hungary did infectious diseases account for about 4.5% of all natural deaths; in the other countries they accounted for only about 1--2%. In the United States, Sweden, Czechoslovakia and Canada a clearly higher relative number of deaths (about 9--13%) were due to diseases of the digestive system than in the other countries (about 3--9%), whereas the relative numbers of deaths from respiratory and genitourinary diseases were uniform among all selected countries. Only in Denmark and Norway was a prominent proportion of the deceased (3.5--9.5%) certified as having died due to some symptom or ill-defined condition. About 90% of all middle-aged men died in each country from various diseases of the above six main ICD categories. As a whole, the above single deviations from the general trend were so small that the present results do not support the view that the differences in certifying and coding practices could explain the significant differences found in cardiovascular mortality of middle-aged men between various countries.

The epidemiology of autopsies in cardiovascular deaths of middle-aged men in Finland in 1973

There were 414 certified deaths from cardiovascular diseases (CVD) in men aged 35--44, and 1372 at ages 45--54, in Finland during 1973. A detailed analysis of the examination of the cause of death in these cases was made by paying specific attention to the autopsy epidemiology. In men aged 35--44 years 68.6% of all cardiovascular deaths and 55.2% at ages 45--54 was verified by autopsy. The autopsy rate of cardiovascular deaths in these two populations of deceased males (1) was in 1973 about three times higher than it had been 10 years earlier, (2) decreased significantly with the age of the deceased population, (3) was higher in urban than in rural areas, (4) was markedly higher in Helsinki than anywhere else in Finland (at ages 35--44 the rate in Helsinki was 94.9% and at 45--54 76.2% in 1973), (5) was dependent on the actual place of death, (6) was higher than the mean rate recorded for all natural deaths in these two groups of male deceased, (7) was higher in the category of cerebrovascular deaths and lower in deaths from ischaemic heart diseases than the mean rate recorded for all cardiovascular deaths, and (8) was composed mainly of medicolegal autopsies, when the cause of death was some ischaemic or functional heart disease; mostly a clinical autopsy was made when the death was due to some other category of CVD. In addition, 76% of the deceased 35--54-year-old males who died from CVD were either autopsied and/or treated in a hospital before death. This result and the quite high national autopsy rates among the deceased young and middle-aged populations give support to the reliability of the national mortality statistics at these ages.

Primary prevention of coronary heart disease: a critique

The question is whether alteration of risk factors will aid primary and secondary prevention of coronary heart disease. Critical review of available evidence indicates that inferences have been made about the beneficial effects of risk factor modification without an adequate test of the hypothesis. Trial interventions to assess the efficacy of serum cholesterol-lowering measures have had negative or equivocal results. It remains to be seen whether the findings of clinical trials on hypertension can be applied toward primary prevention of coronary heart disease in the community. The cigarette smoking habit seems to be unique among coronary heart disease risk factors. The evidence appears sufficient to justify serious consideration of a strategy of preventing the smoking habit now, persuading patients to stop and encouraging teenagers not to start.

Life events before myocardial infarction

One-hundred and-twenty-one men between the ages of 35 and 65 who had been admitted to a Coronary Care Unit were interviewed within a mean of 2.3 days of that admission, concerning their experience of certain specified predesignated life events in the previous three months before myocardial infarction. Ninety-one of them who were proven to have sustained a myocardial infarction were randomly matched individually with 91 men from an industrial payroll for sex, age and occupational level. Both groups matched, as groups, on marital status and household size. Significantly more patients (p less than .01) than comparison subjects reported these life events in the three weeks before infarction, whether this was experienced acutely or in an anginal setting. Most events were apparently independent of patients' or comparison subjects control; these were reported significantly more often by patients, both during the entire 12 weeks prior to illness (p less than .01) and during the three weeks immediately before infarction (p less than .02). Methodological difficulties are delineated which hinder credence as to the role of life events before illness.

Myocardial infarction in young women

This study of 24 women under age 40 years with myocardial infarction demonstrates that even in young women myocardial infarction is most commonly due to coronary atherosclerotic heart disease. Other causes of coronary occlusion were documented in 17% of these patients, indicating that these lesser causes of myocardial infarction are more common in young women than in older persons or in young men. In those patients with coronary atherosclerosis one or more significant risk factors could usually, but not always, be documented. The clinical manifestation of the coronary occlusion in the study group was not unlike its manifestation in groups of different ages or sex, or both.

Angina pectoris among 10,000 men. II. Psychosocial and other risk factors as evidenced by a multivariate analysis of a five year incidence study

The major independent role played by anxiety and severe psychosocial problems (especially family ones) is demonstrated by this multivariate analysis of a five year prospective study of the development of new angina pectoris among almost 10,000 adult men (average annual incidence = 5.7/1,000). The independent effect of these two variables is considerably augmented by the other significant risk factors of age, total serum cholesterol, systolic or diastolic blood pressure, certain electrocardiographic abnormalities and diabetes mellitus. The presence of all seven risk factors (at a high level) increases the probability of angina pectoris developing within five years to 289/1,000 from 14/1,000, when these factors are low or absent. The wife's love and support is an important balancing factor, which apparently reduces the risk of angina pectoris even in the presence of high risk factors. The implications of these findings to the pathophysiology and prevention of angina are stressed.