Established Coronary Heart Disease Risk Research Articles

Helicobacter pylori and atherosclerosis: Can current data be useful for clinical practice?

We very much appreciate to read the letter to the Editor from Drs Pellicano R and Fagoonee S [1] with relevant comments to our recent article [2]. They critically remarked the usefulness and the generalized message encouraging Helicobacter pylori eradication to prevent coronary artery disease (CAD) or its recurrence. Indeed, the lack of association between H. pylori infection and atherosclerotic cardiovascular diseases has also been observed by some papers with conflicting results [3]. However, the data o, significant association between infection in general (H. pylori in particular) and CAD with evidence level III are more frequent than conflicting results. Despite the limitations of our hospital-based data concerning “Prevention of the metabolic syndrome insulin resistance and the atherosclerotic diseases in Africans infected by Helicobacter pylori infection and treated by antibiotics” [2], of great interest are the case-control and the longitudinal approach of the methods procedure within a homogenous Bantu ethnic group. There were both chronic and acute (stroke, angor pectoris myocardial infarction) atherosclerotic diseases within a specific environment. Atherosclerosis was anecdotally reported in Africa during 1900s, but emerging now with epidemic rates [4]. Established coronary heart disease risk factors account for only about one third of acute events [5] and do not fully explain the temporal and geographical variations in CAD worldwide. Each region of sub-Saharan Africa has its peculiar expressing of epidemiological and clinical features of atherosclerosis [5]. This has fostered the search for causal association between different components of the metabolic syndrome, atherosclerotic cardiovascular diseases and H.

Impact of mean arterial blood pressure on higher arterial stiffness indices in South Asians compared to white Europeans

The pathophysiology of excessive premature coronary heart disease mortality among South Asians living in Britain remains unclear. We hypothesized that higher measures of arterial stiffness among South Asians compared with their white European counterparts would reflect an earlier progression of atherosclerosis, even in the absence of established coronary heart disease risk indices. Arterial stiffness was measured by digital volume pulse photoplethysmography in 90 healthy South Asians and compared with 62 matched white Europeans in a temperature-controlled environment using a direct, standardized approach. Both ethnic groups were comparable for coronary heart disease risk profiles and had similar 10-year coronary heart disease risk estimates, but South Asians had a greater mean (SD) stiffness index compared with white Europeans [9.39 (0.22) vs. 8.43 (0.23) m/s; P = 0.007]. On linear regression analysis, mean arterial blood pressure (beta = 0.06; P = 0.03) and age (beta = 0.11; P = 0.002) were independent predictors of arterial stiffness in South Asians. Among white Europeans, age was an independent predictor of arterial stiffness (beta = 0.05; P = 0.01). Healthy South Asians have increased systemic arterial stiffness measured by stiffness index compared with white Europeans. There was an adverse and disproportional impact of age and mean arterial pressure on the vascular system in South Asians. Increased indices of arterial stiffness may explain their increased susceptibility to coronary heart disease.

Clinical Depression and Risk of Out-of-Hospital Cardiac Arrest

The association of depression with coronary heart disease-related mortality has been widely recognized. This finding may partly reflect an association between depression and sudden death, in part because the imbalance between sympathetic and parasympathetic tone is altered in depressed subjects. We, thus, investigated whether the presence and severity of clinical depression was associated with a higher risk of sudden cardiac death. We used data from a population-based case-control study of risk factors for incident out-of-hospital cardiac arrest (CA) conducted among enrollees of a health maintenance organization in western Washington State. Cases (n = 2228) were aged 40 to 79 years and experienced CA between January 1, 1980, and December 31, 1994. Controls (n = 4164) were a stratified random sample of enrollees defined by calendar year, age, sex, and prior heart disease. Clinical depression was defined as physician diagnosis of depression or use of antidepressant treatment within the year before the event. Referral to mental health clinics or hospitalization for depression defined severe depression. Clinically depressed patients had a higher odds ratio (OR) of CA (1.88; 95% confidence interval [CI], 1.59-2.23), which persisted after adjustment for confounders (OR, 1.43; 95% CI, 1.18-1.73). The association was observed in both sexes, in various age groups, and in subjects with prior physician-diagnosed heart disease (OR, 1.27; 95% CI, 1.01-1.60) and without prior physician-diagnosed heart disease (OR, 1.71; 95% CI, 1.22-2.41) (P = .13 for the interaction). Compared with nondepressed subjects, the risk of CA was increased in less severely depressed subjects (OR, 1.30; 95% CI, 1.04-1.63) and further increased in severely depressed subjects (OR, 1.77; 95% CI, 1.28-2.45) (P<.001 for trend). Clinical depression may be associated with a higher risk of CA independently of established coronary heart disease risk factors.

The effect of type 1 diabetes mellitus on the gender difference in coronary artery calcification

OBJECTIVESTo examine whether the gender difference in coronary artery calcification, a measure of atherosclerotic plaque burden, is lost in type 1 diabetic patients, and whether abnormalities in established coronary heart disease risk factors explain this.BACKGROUNDType 1 diabetes abolishes the gender difference in coronary heart disease mortality because it is associated with a greater elevation of coronary disease risk in women than men. The pathophysiological basis of this is not understood.METHODSCoronary artery calcification and coronary risk factors were compared in 199 type 1 diabetic patients and 201 nondiabetic participants of similar age (30 to 55 years) and gender (50% female) distribution. Only one subject had a history of coronary disease. Calcification was measured with electron beam computed tomography.RESULTSIn nondiabetic participants there was a large gender difference in calcification prevalence (men 54%, women 21%, odds ratio 4.5, p < 0.001), half of which was explained by established risk factors (odds ratio after adjustment = 2.2). Diabetes was associated with a greatly increased prevalence of calcification in women (47%), but not men (52%), so that the gender difference in calcification was lost (p = 0.002 for the greater effect of diabetes on calcification in women than men). On adjustment for risk factors, diabetes remained associated with a threefold higher odds ratio of calcification in women than men (p = 0.02).CONCLUSIONSIn type 1 diabetes coronary artery calcification is greatly increased in women and the gender difference in calcification is lost. Little of this is explained by known coronary risk factors.

Dental infections and atherosclerosis

In most countries, coronary heart disease is one of the leading causes of morbidity and death. This report reviews the current evidence indicating that oral conditions (specifically periodontitis) may be a risk factor for atherosclerosis and its clinical manifestations and provides new preliminary data. This review is done in the context of the research indicating that inflammation plays a central role in atherogenesis and that there is a substantial systemic microbial and inflammatory burden associated with periodontal disease. Our review concentrates on 5 longitudinal studies that show oral conditions being associated with the onset of coronary heart disease while controlling for a variety of established coronary heart disease risk factors. In addition to published evidence, preliminary findings from our Dental Atherosclerosis Risk in Communities study also indicate that periodontal disease is associated with carotid intimal-medial wall thickness, a measure of subclinical atherosclerosis, adjusting for factors known to be associated with both conditions. (Am Heart J 1999;138:S528-S533.)

Cardiothoracic ratio and relative heart volume as predictors of coronary heart disease mortality. The Whitehall study 25 year follow-up.

To examine the association of radiographic measures of heart size with mortality from coronary heart disease. One thousand, one hundred and ninety-one male civil servants aged 40-69 years were followed-up for mortality over 25 years in relation to cardiothoracic ratio and relative heart volume. A high cardiothoracic ratio and relative heart volume predicted coronary (n = 196 deaths) and all-cause mortality, but not respiratory or malignant mortality. After adjustment for age, systolic and diastolic blood pressure, the highest (> or = 0.47) compared to the lowest quintile of the cardiothoracic ratio (< 0.40) was associated with a rate ratio of 1.84 (95% CI 1.14-2.97) for the effect on coronary heart disease mortality. Further adjustment for heart rate, smoking, cholesterol, angina and ECG ischaemia had little effect, reducing the rate ratio to 1.65 (95% CI 1.01-2.70). Similar rate ratios were observed for relative heart volume. Cardiothoracic ratio within the range considered 'normal' in clinical practice predicted coronary heart disease mortality independent of established coronary heart disease risk factors. The relative heart volume, which uses measurements from the lateral as well as the posteroanterior chest X-ray, did not predict coronary heart disease any better than the cardiothoracic ratio. The extent to which left ventricular mass and systolic dysfunction-- pathophysiological correlates of the cardiothoracic ratio and relative heart volume--are independent risk factors for coronary heart disease should be further investigated.

Mechanisms whereby oestrogens influence arterial health.

Coronary heart disease (CHD) is uncommon in premenopausal women compared with men of similar age, but its incidence increases after the menopause to reach that of men. There is now good population-based evidence that hormone replacement therapy (HRT) in postmenopausal women reduces the incidence of CHD, perhaps by up to 50%. Oestrogens have a beneficial effect on arterial health in many different ways. HRT may both reduce the risk of atheroma formation and improve arterial function. Depending on the formulation, HRT can lower LDL and triglycerides, and increase HDL. Oestrogen may also produce qualitative as well as quantitative improvements in lipoproteins. It can improve insulin resistance and hence carbohydrate metabolism, and may enhance fibrinolysis rather than coagulation. Thus these effects of HRT on risk factor for CHD will reduce the risk of atheroma development and progression. Oestrogen has direct effects on blood vessels and improves vascular function through various mechanisms including endothelium-dependent and calcium-dependent processes. HRT should therefore now be considered for use in postmenopausal women with established CHD risk.

Awareness of High Blood Pressure Stimulates Platelet Release Reaction

The present study aimed at testing the hypothesis of a link between mental stress and blood platelet function. Twenty-nine 19-year-old men were recruited from the 98th percentile of mean blood pressure (116 mmHg) at a routine medical screening. They were not informed about their elevated blood pressures at the time of the screening. One year later they were randomized into two groups. Group 1 (n = 16) was exposed to mental stress by a letter informing them about their high blood pressure, while group 2 (n = 13) was sent a neutral letter. At an examination 2 weeks later, heart rate (p less than 0.05) and plasma adrenaline (p less than 0.05) responses to a cold pressor test were exaggerated in the informed group. The plasma beta-thromboglobulin (beta TG) concentration was elevated in the informed group (p less than 0.05) as was mean blood pressure (p less than 0.05). beta TG correlated positively with hematocrit (r = 0.59, p less than 0.005) and mean blood pressure (r = 0.43, p less than 0.05), and negatively with plasma HDL (r = -0.61, p = 0.001). The study shows that awareness of hypertension induces a hyperadrenergic state which is associated with the platelet release reaction. Under these circumstances platelet release seems to be correlated to established coronary heart disease risk factors.

Risk factors, exercise fitness and electrocardiographic response to exercise in 12,866 men at high risk of symptomatic coronary heart disease

The association between coronary heart disease (CAD) risk factors with submaximal exercise performance was examined among 12,866 men at high risk in the Multiple Risk Factor Intervention Trial (MRFIT). Men were selected from a risk score based on serum cholesterol level, diastolic blood pressure and number of cigarettes smoked per day. Multivariate analysis using exercise ST depression as the dependent variable showed age, diastolic blood pressure and serum cholesterol level were significant positive predictors of ST depression and cigarettes per day, body mass index and heart rate at rest were significant negative predictors of ST depression. Similarly, multivariate analysis, using exercise duration as the dependent variable, revealed that age, cholesterol level, body mass index and heart rate at rest were significant negative predictors of exercise duration, whereas cigarettes per day and leisure-time physical activity were significant positive predictors. Some of these relationships with exercise performance are consistent with established epidemiologic CAD risk factor associations and others are not. The MRFIT selection process, which resulted in smokers who were significantly younger and who had significantly lower levels of other CAD risk factors than nonsmokers, was partially responsible.