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Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effectiveness of treatment for mild hypertension (diastolic pressures of 85 to 105 mm Hg) has not been conclusively demonstrated. Both the costs of a carefully designed clinical trial and the likelihood that it will produce definitive answers will depend importantly on the sample size. This paper presents sample-size estimates under a variety of assumptions regarding the characteristics of the population to be studied, the degree of blood pressure control to be achieved, and the health benefits to be expected. Under a central set of assumptions, the estimated sample size per group is 22,700 with death as an endpoint and 14,000 with morbid events (CHD and stroke) as endpoints. As individual assumptions are varied one at a time, required sample sizes range from 10,900 to 101,100 and from 6,800 to 63,100 for the respective endpoints. Results are most sensitive to the degree of blood pressure control actually achieved to the expected health benefits from blood pressure control. They are also highly sensitive to the sex composition of the population and to expected dropout rates. The choice of sample size will depend on the decision maker's assessment of the likelihood that each assumption will be fulfilled and on the degree of willingness to risk an inconclusive study result. By making explicit the effect of variation in each assumption, decision making is rendered more susceptible to critical examination by outside reviewers.
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PMID:Sample-size estimation: a sensitivity analysis in the context of a clinical trial for treatment of mild hypertension. 37 22

Total mortality showed no association with heavy coffee consumption in the four race-sex groups of Evans County. Deaths from coronary heart disease in WM, WF and BM showed no statistically significant differences between the two coffee consuming groups. Sex differences in cerebrovascular death rates, consistent in both races, suggest the possibility for a female excess of stroke deaths among coffee drinkers, and a "protective" effect of coffee drinking among males. Thus, in an area of the United States which has been designated the "Stroke Belt", neither the cardiovascular nor the cerebrovascular death rates seem strongly nor consistently related to coffee drinking habits. Although the number of deaths (339) is fairly large, representing a 13% mortality in this community over a four and one-half year observation period, the classification in four race-sex groups with further division into the groups with different coffee drinking habits limits each stratum to rather small numbers. In addition, 86 cases of CHD and CVD were diagnosed during lifetime already and, therefore, were excluded from the prospective mortality study. Confidently to refute or confirm the allegations of a detrimental influence of high coffee intake on ischemic heart disease one would need larger numbers. But in the light of our most important finding--that mortality from all causes is not increased in the high coffee consuming group--the finding of increased ischemic heart disease death rates with high coffee consumption would have to be compensated by a provocative, lower rate for other causes of death.
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PMID:Coffee consumption and mortality in a community study--Evans Co., Ga. 96 3

The City of Bergen was covered by a Mass Miniature Radiology Survey in 1963-64. On the initiative of the University of Bergen, examinations of BP were included. The initial survey has been reported previously (1). This analysis concerns the relationship between the 5 1/4-year cause-specific mortality and BP. Non-attenders have excess mortality in relation to attenders and this is mostly explained by a generally high mortality among bedridden people. The age-specific total mortality shows a clear pattern of a general increase with increasing BP. At high systolic BP levels, the 5-year mortality is independent of whether the age is 45 or 75. The systolic age-adjusted curve for males increases quite linearly, while the diastolic curve is more U-shaped. Thus, when comparing the predictive power of BP, allowance must be made for this fact. Using a second order polynomial prediction function, this conclusion is reversed. The mortality from cerebral stroke shows a dramatic increase with increasing BP. The diastolic curve shows a bend-off for high values, above 110 mmHg. This may be due to the offer of treatment which such patients received after the screening. Also the CHD mortality curve flattens for high BP values, especially for diastolic BP.
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PMID:Five-year mortality in the city of Bergen, Norway, according to age, sex and blood pressure. 97 Feb 30

The main points covered in this review are as follows: 1. Hypertension is a major determinant of cardiovascular disease (CVD). As such it is a major cause of mortality, potential years of life lost, morbidity and long-term disability. 2. The incidence of CVD is directly related to BP. It is likely that this extends over the full range of BP although some writers believe that a J-curve of risk exists for CHD. 3. The relationship between long-term disability from CVD and BP requires further study. 4. Because of regression dilution bias, the gradient in risk of stroke and CHD with BP has been underestimated in the past. Recent research suggests that the risk of stroke increases at least tenfold and CHD sixfold over a range of usual DBP of 30 mmHg (equivalent to approximately 50 mmHg baseline DBP). 5. The population attributable risk (PAR) of CVD related to general elevation of BP in the population from a mean daily excess of sodium intake of 100 mmol/day is at least 30%. In typical industrialised countries the PAR for stroke and CHD from clinical hypertension is 36% and 22%, respectively. These estimates of PAR provide a guide to the maximum benefit that could result from either restriction of sodium intake in the whole population or ideal management of all persons with hypertension. In practice such targets are unlikely to be realised. 6. Recent analyses of clinical trials of treatment of hypertension suggest that the risk of stroke is reduced at all levels of initial BP to the extent predicted from observational studies.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Review of the benefits of treating hypertension. 129 6

OBJECTIVE--To investigate the relationship between asymptomatic hyperglycemia (IGT or newly diagnosed NIDDM) and atherosclerotic vascular disease. RESEARCH DESIGN AND METHODS--A representative cross-sectional population sample of 1431 subjects (511 men, 920 women; 65-74 yr old). Altogether, 312 men and 515 women had NGT, 84 men and 158 women had IGT, 33 men and 59 women had newly diagnosed NIDDM, and 82 men and 188 women had previously diagnosed NIDDM. Participation rate was 71%. Main outcome measures were prevalence rates of CHD, stroke, and intermittent claudication. RESULTS--There was no difference in the prevalence of definite or possible MI verified at hospital between subjects with asymptomatic hyperglycemia and NGT (15.5 vs. 13.3% in men, 6.3 vs. 5.3% in women). Men with asymptomatic hyperglycemia had 1.5 x higher prevalence of angina pectoris (29.4 vs. 19.3%, P less than 0.05), major Q-QS changes (21.1 vs. 12.0%, P less than 0.05), ischemic ECG changes (59 vs. 45%, P less than 0.05), and silent MI on ECG (14.8 vs. 7.9%, P less than 0.05) compared to men with NGT. Women with asymptomatic hyperglycemia had more often ischemic ECG changes compared to women with NGT (48.3 vs. 39.7%, P less than 0.05). There was no difference (NS) in the prevalence of verified stroke (3.5 vs. 4.6% in men, 2.7 vs. 2.5% in women) or claudication (7.0 vs. 7.7% in men, 4.6 vs. 4.3% in women) between subjects with asymptomatic hyperglycemia and NGT. In multiple logistic regression analyses, the association between risk factors and MI or ischemic ECG changes in subjects with asymptomatic hyperglycemia was not consistent. CONCLUSION--Elderly subjects with asymptomatic hyperglycemia (particularly men) tended to have an increased prevalence of CHD. Thus, asymptomatic hyperglycemia in the elderly is not a benign phenomenon but is associated with cardiovascular morbidity.
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PMID:Asymptomatic hyperglycemia and atherosclerotic vascular disease in the elderly. 150 3

The importance of the thrombotic component of coronary heart disease is increasingly recognised, and in particular the role of the coagulation system in this process. The Northwick Park Heart study was the first major prospective study to identify both fibrinogen and factor VIIc as risk factors, as powerful as total cholesterol in predicting ischaemic events. Since then, a number of epidemiological studies have confirmed the importance of fibrinogen, not just in CHD but in stroke as well. A variety of environmental factors are known to influence levels of factor VII and fibrinogen and therefore support their role in the development of coronary thrombosis. Both are known to increase with age and body weight and are relatively elevated in diabetes. Fibrinogen is strongly related to smoking habit and a substantial proportion of the IHD risk associated with smoking is mediated through this relationship. There is a dose response effect between number of cigarettes smoked and level of fibrinogen and an inverse relationship with time since cessation of the habit. Factor VII is known to correlate with total cholesterol level, and there is a relationship between dietary variability of fat intake and factor VII, which is likely to play an important role in the risk of CHD. The case for using either anticoagulation or anti platelet agents in secondary prevention of myocardial infarction is now clear, but there are still uncertainties in primary prevention which relate to the ideal dose intensity of either aspirin or anti-coagulation and the type of patient most likely to benefit. The ongoing Thrombosis Prevention Trial identifies middle-aged males at high risk of a myocardial infarction.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Plasma fibrinogen and factor VII as risk factors for cardiovascular disease. 150 57

The question whether there is a level of diastolic pressure during treatment below which further reduction of pressure may be harmful rather than beneficial is of great interest. If, as the proponents of this hypothesis maintain, death from CHD among treated hypertensives becomes more rather than less common at very low diastolic pressure, this might explain at least in part why most primary prevention trials of hypertension have failed to show a reduction in CHD mortality. However, as the sceptics have pointed out, the evidence that drug induced lowering of blood pressure is harmful is not of the highest quality, and alternative explanations for excess cardiovascular mortality at low diastolic pressure exist. In the following review of this hotly contested debate it is concluded that both proponents and sceptics may be correct, but that the presence of a J curve should not divert attention from the main benefit of treating hypertension which is a reduction in the risk of fatal and non fatal stroke.
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PMID:Is there a J curve distribution for diastolic blood pressure? 154 Oct 33

Total and regional (by 7 zones) contractility of left ventricular functions in 25 patients with hypertrophic cardiomyopathy (HCMP) were characterized by a different combination of normal and elevated values of total and regional ejection fractions, rate indices of systolic expulsion. Normal or slightly changed values of the end-diastolic volume were combined with normal or elevated values of the stroke volume. Comparative analysis of the values characterizing cardiodynamics, led to working out criteria of differential diagnosis in HCMP patients with heart pain and in CHD patients with myocardial hypertrophy (predominance of the signs of left ventricular hyperfunction in the former and contractility hypofunction and asynergy in the latter). Changes in the diastolic filling of the left ventricle indicated its disturbed diastolic function in both groups of patients.
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PMID:[Radionuclide ventriculography in the diagnosis of hypertrophic cardiomyopathy]. 165 88

In this paper a computer simulation model for cost-effectiveness analysis of cardiovascular disease prevention is presented. Cost-effectiveness analysis makes it possible to compare the cost-effectiveness of different interventions in order to maximize the health effects for a given amount of resources. The computer simulation model was written in Turbo-Pascal to be used on an IBM-PC-compatible. The model was based on the 8-year logistic multivariate risk equations for CHD and stroke from the Framingham Heart Study, but the regression coefficients can easily be changed if local data exist. The main advantages with the model are that it is easy to use, transparent, and flexible. The model was mainly developed for scientific purposes, but should be useful also for educational purposes and clinical decision analysis. The modelling approach used should also be useful in many other medical areas.
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PMID:A computer simulation model for cost-effectiveness analysis of cardiovascular disease prevention. 176 71

Risk of cardiovascular events was determined over 24 years of surveillance in relation to general adiposity reflected by relative weight and by regional obesity estimated by skinfolds and waist girth per inch of height. Upper quintile values of relative weight, subscapular skinfolds and waist girth were each associated with increased risks of cardiovascular disease in both sexes. Risk of total cardiovascular events increased with the degree of regional, central or abdominal obesity. Mortality from cardiovascular disease was also increased. Increased relative weight and central obesity were both associated with increased risk factors including cholesterol, blood pressure, glucose and uric acid. Changes in weight were mirrored by changes in risk factors with linear trends over a 15 lb range of weight fluctuations. Subscapular skinfold and the ratio of subscapular-to-triceps skinfold, measures of central obesity, were in either sex also associated with an increased probability of coronary attacks in particular. The subscapular skinfold contributed to CHD risk independent of body mass index (BMI). Multivariate analyses taking all the risk factors into account indicate an independent effect of abdominal obesity on stroke, cardiac failure and cardiovascular and all-cause mortality in men. In women, only the subscapular-to-triceps skinfold ratio independently contributes to CHD, cardiovascular and all cause mortality. Regional obesity appears to be an independent contributor to cardiovascular disease at a given level of general adiposity, its effect only partially mediated through promotion of other known risk factors. These data suggest that cardiovascular disease is as closely linked to abdominal as to general adiposity.
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PMID:Regional obesity and risk of cardiovascular disease; the Framingham Study. 199 75


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