Long term changes in blood pressure and risk of cerebrovascular disease

Blood Pressure Trajectories and the Risk of Intracerebral Hemorrhage and Cerebral Infarction: A Prospective Study

The association between long-term blood pressure (BP) patterns in community-dwelling adults and risk of intracerebral hemorrhage and cerebral infarction is not well characterized. This prospective study included 79 385 participants, free of stroke, myocardial infarction, and cancer in or before 2010 (baseline). Systolic BP trajectories were identified using latent mixture modeling with data from 2006, 2008, and 2010. Incident cases of intracerebral hemorrhage and cerebral infarction occurred during 2010 to 2014, confirmed by review of medical records, by 3 physicians. We identified 5 distinct systolic BP trajectories during 2006 to 2010. Each of the trajectories was labeled according to their BP range and pattern over time: normotensive-stable (n=26 740), prehypertension-stable (n=35 674), stage 1 hypertension-increasing (n=8215), stage 1 hypertension-decreasing (n=6422), and stage 2 hypertension-stable (n=2334). We documented 1034 incident cases of cerebral infarction and 187 cases of intracerebral hemorrhage. Although the prehypertension-stable trajectory exhibited systolic BP range within the normal range (120-140 mm Hg) during 2006 to 2010, this group had higher stroke risk relative to the normotensive-stable group (<120 mm Hg) (adjusted hazard ratio was 3.11 for intracerebral hemorrhage and 1.99 for cerebral infarction; P<0.001 for both), after adjusting for possible confounders. Individuals in the stage 2 hypertension-stable systolic BP trajectory (175-179 mm Hg) had the highest risk of intracerebral hemorrhage (adjusted hazard ratio was 12.4) and cerebral infarction (adjusted hazard ratio was 5.07), relative to the normotensive-stable group (P<0.001 for both). BP trajectories were associated with the risk of stroke and increasing BP trajectories within the currently designated normal range may still increase the risk for stroke.

Cohort Profile: The Manitoba Follow-up Study (MFUS)

The Manitoba Follow-up Study (MFUS) is Canada's longest running study of cardiovascular disease and ageing. The MFUS cohort consists of 3983 men recruited from the Royal Canadian Air Force at the end of World War II. At entry to the study, 1 July 1948, their mean age was 31 years, with 90% between ages 20 and 39 years. All study members were free of clinical evidence of ischaemic heart disease. The protocol of MFUS was to obtain routine medical examinations from these men at regular intervals over time. The research goal of the study was to examine the role that any abnormalities detected on routine electrocardiograms from apparently healthy men might play in the prediction of subsequent diagnoses of cardiovascular disease. Over the course of 65 years, about 35% of the cohort has documented evidence of ischaemic heart disease. The research focus was expanded in 1996 to explore the roles of physical, mental and social functioning in support of healthy and successful ageing. On 1 July 2013, 429 original cohort members were alive with a mean age of 92 years. Collaborative research with others outside the in-house team is welcomed.

Comparison of vascular stiffness in vascular dementia, Alzheimer dementia and cognitive impairment

Abstract Defining the vascular component(s) of the clinical diagnosis of vascular cognitive impairment (VCI) and vascular dementia (VaD) continues to be problematic. The goal of this study was to determine whether vascular stiffness, measured by pulse wave velocity (PWV), is altered in VaD, to study the utility of PWV in differentiating VaD from Alzheimer dementia (AD) and the relationship between PWV and cognitive function. A qualitative and quantitative structured analysis of the literature was conducted until September 2010, using a search strategy based on the key words: dementia, vascular dementia, dementia of vascular origin, cognitive function and arterial stiffness or pulse wave velocity. Seventeen studies assessed large vessel vascular stiff by PWV and related it to cognitive function or dementia. Six of these studies compared PWV in 154 persons with VaD, 207 with AD and 197 controls without dementia. Mean PWV was significantly (p < 0.0001) higher in VaD compared with controls. Mean PWV was significantly (p = 0.002) higher in VaD compared with AD. Fourteen studies examined the relationship between PWV and cognitive function. The majority of studies (nine of 14) reported a significant correlation between PWV and cognitive function. Four of eight studies that evaluated the relation using univariate analysis reported a significant correlation of PWV with the Mini Mental State Exam (MMSE) or Hasegawa Dementia Scale, and the correlation with MMSE between studies showed a close agreement of correlation coefficients (0.206 to 0.27). In multivariate analysis, adjusted for a wide range of possible confounding factors, the majority or 80% (eight out of 10) studies comprising a population of 6,034 individuals found a significant inverse relationship between PWV and cognitive function. In summary, vascular stiffness is inversely related to cognitive function. Vascular stiffness is greater in VaD compared with AD, suggesting PWV may be useful in identifying VaD.

Characteristics of stroke in Hofuf, Saudi Arabia

BACKGROUND

Stroke is a common neurological disorder that is encountered in most hospitals in both developed and developing countries. This two-year study was designed to show the characteristics of the problem at the King Fahad Hospital, Hofuf, Saudi Arabia.

PATIENTS AND METHOD

This was a prospective study of all Saudi stroke patients admitted to the medical wards in the study period. All patients were assessed individually by one of the two available neurologists. Data was collected on pre-designed protocol, and analysis was performed using tables and figures, and EpiInfo A(R) computer software.

RESULTS

The 329 Saudi patients studied fulfilled the criteria for stroke. The male:female ratio of the patients was 1:1, and their ages ranged between 42 and 92 years (mean 62.8+/-11.1) for males, and between 20 and 100 years (mean 59.6+/-15.4) for females. The relative frequencies of stroke subtypes were ischemic infarcts (79%), of which 46% were lacunar infarcts, intracerebral hemorrhage (18.8%), and subarachnoid hemorrhage (2.2%). The most common risk factor was concomitant hypertension with diabetes mellitus (40.4%), hypertension alone (24.9%), diabetes alone (11.6%), atrial fibrillation (5.8%), other cardiac factors (5.5%), transient ischemic attack (TIA) and prior stroke (2.1% each), and smoking (1.8%). No risk factor was detected in 5.8% of the patients. The overall in-hospital mortality was 10.0%, with a significant male preponderance.

CONCLUSION

This study demonstrated that stroke is a common neurological condition in the Al-Hassa region of the Kingdom. The male:female ratio was dissimilar from that observed in other parts of Saudi Arabia. The study also showed that hypertension with diabetes constituted a potent risk factor. Sickle cell anemia was not found to be a risk factor. The case fatality was low and both the incidence and mortality showed seasonal preference. We believe that there is a need to establish a Stroke Register at the King Fahad Hospital at Hofuf for the Al-Hassa region.

Italian multicenter study of reversible cerebral ischemic attacks. Part 5. Risk factors and cerebral atherosclerosis

As part of a prospective study, the influence of several premorbid and environmental factors on the presence, extent and severity of cerebral vessel atherosclerosis was studied in 462 patients with clinical diagnosis of RIA who underwent cerebral angiography. The extent and severity of atherosclerosis of the cerebral vessels was quantified using extracranial and intracranial cerebrovascular scores (ECS, ICS) based on the number and severity of the lesions in 11 extracranial and 21 intracranial arterial segments. Results of univariate and multivariate analyses indicate that the presence of atherosclerotic changes of cerebral vessels, as shown by angiography, was strongly related with age in both sexes. The lesions were more frequent in males, in particular under age 55. Elevated cholesterol was associated with a higher incidence of atherosclerotic lesions. Smoking was associated with a higher incidence of extracranial lesions. Age, smoking and history of hypertension were the best predictors of the extent and severity of cerebral vessel atherosclerosis.

An overview of stroke. Epidemiology, classification, risk factors, clinical aspects

Although evidence indicates that the incidence of stroke has declined over the past 30 years, stroke remains one of the leading causes of disability and death in the United States. Prevention appears to be the best treatment. According to the Straub Stroke Registry, 52% of strokes in its patient population can be attributed to a thrombotic mechanism. Besides thrombosis, the major causes of stroke are embolism, lacunar infarct, cerebellar infarction, and hemorrhage. Hypertension is a widely recognized risk factor for stroke, but the risks vary for each type of stroke. Transient ischemic attacks may precede stroke and thus are a warning signal. Since acute stroke cannot be cured, management includes symptomatic care and control of related problems such as hypertension. Carotid endarterectomy is useful in prevention of initial or recurrent stroke. The prognosis of stroke patients varies depending on the size of the lesion.

Effectiveness of treatment with antihypertensive drugs and trends in mortality from stroke in the community

A study was made of the changes in the treatment of hypertension, in the effectiveness of that treatment, and in mortality from cerebrovascular stroke in men and women in two counties in Finland. One of these counties was North Karelia, where a comprehensive cardiovascular programme based in the community had been launched in 1972. Cross sectional surveys in large representative samples of the middle aged populations were carried out in 1972, 1977, and 1982. Average annual mortality from stroke adjusted for age was calculated for the two year periods 1971-2, 1977-8, and 1980-1. The proportion of hypertensive men being effectively treated for their hypertension increased in both areas from 1972 to 1977 and further from 1977 to 1982. Mortality from stroke in middle aged men decreased in both areas during both observation periods. The proportion of hypertensive women being effectively treated greatly increased in both areas from 1972 to 1977. This was associated with a large decline in mortality from stroke. In North Karelia the proportion of women being effectively treated was remarkably high but decreased somewhat between 1977 and 1982; this decrease was associated with an increase in mortality from stroke in the women aged 35-64. These results support the idea that effective antihypertensive treatment in the community is a major determinant of mortality from stroke in both men and women.

Relationship between longitudinal changes in blood pressure and stroke incidence

The relationship of changes in blood pressure with time to stroke incidence was examined on members of the Adult Health Study sample who have participated in biennial clinical examinations at the Radiation Effects Research Foundation since their inception in 1958. The regression coefficient of blood pressure regressed on time (the increase in blood pressure per cycle) was used as an index of the change in blood pressure with time. Cox's regression analysis, a technique which is suitable for follow-up studies was used. The data suggest that a single blood pressure measurement is not sufficient for predicting risk; the accumulated value or average over a period of time should be considered for this purpose. In addition to the actual blood pressure, the increase in blood pressure with time is a risk factor, particularly for cerebral hemorrhage. Cerebral hemorrhage was more strongly related to diastolic than to systolic blood pressure, while cerebral infarction appeared to be more strongly related to systolic than to diastolic blood pressure.

Hemiplegics after a first stroke: late survival and risk factors

Scanning 3000 cases admitted for rehabilitation after cerebrovascular accident over a 20 year period produced a sample of 1369 subjects, without age restrictions, admitted within six months of a first stroke of thrombotic etiology. In this sample, survival rates showed no significant difference between men and women. Age at onset, however, clearly influenced survival changes; the expected mean survival was 6 years at 40 and 2 at age 80; average loss of life was 14 years for the whole sample, meaning a vital prognosis two to three times worse than that of the general population. At least 86% of the sample presented one or more of five etiological antecedents to stroke: hypertensive heart disease, peripheral vascular disease, diabetes mellitus, myocardial infarction and atrial fibrillation. In 87% of those, HHD and/or PVD were present. Presence of hypertension significantly lowered life expectancy and so did PVD; their influence is felt from the earliest stages. In contrast, diabetes mellitus, the next most common factor, has a late influence, starting about the fifth year after stroke. MI and AF were present in relatively fewer patients, but they contributed towards a considerable decrease in life expectancy, evident from the first stages, the more drastic reduction being observed in the AF group.

Relation of blood pressure, serum lipids, and smoking to the risk of cerebral stroke. A longitudinal study in Eastern Finland

The impact of blood pressure, serum cholesterol and triglycerides, and smoking on the risk of cerebral infarction and other stroke was studied by a longitudinal design. A random sample of the population aged 35-59 years in two counties of Eastern Finland was examined in 1972, with a participation rate of 92 per cent. In subjects (both sexes) standardized epidemiological measurements on blood pressure, height, weight, and serum lipids were made and questionnaire data were obtained on smoking. The cohort was followed for seven years by means of national hospital discharge and death certificate registers. During the follow-up 77 men and 65 women had a cerebral stroke. Based on multiple logistic risk function analysis, age, smoking, blood pressure, and history of previous stroke and diabetes turned out to be independent predictors of both cerebral infarction and other strokes in men. Diastolic blood pressure of 100 mm Hg or more was associated with a 1.9-fold (90% CI = 1.1-3.6) risk of cerebral infarction in men and 2.5-fold (90% CI = 1.1-5.6) risk in women with no previous stroke. In men 37% (90% CI = 21-53%) of all cerebral strokes were attributable to systolic blood pressure of 150 mm Hg or more and 27% (90% CI = 11-42%) to diastolic blood pressure of 95 mm Hg or more.

Relationship of blood pressure in 20-39-year-old men to subsequent blood pressure and incidence of hypertension over a 30-year observation period

The objective of this investigation was to determine the relationship of blood pressure (BP) in young men, ages 20-39 years, to their subsequent BP from the perspective of BP tracking, position in BP distribution and later evidence of hypertensive BP values. Since 1948, the Manitoba Study group has followed 3983 men, 90% of whom were 20-39 years old at entry. BP in persons not prescribed antihypertensive medications was examined at 5-year intervals during the 30-year observation period to 1978. To adjust for age, BP was examined within 5-year age groups at entry. The correlations between entry and subsequent BP at the same length of follow-up were greater for systolic than diastolic BP and increased with older ages. The correlation decreased wtih every 5-year examination after entry for all ages. Men whose BP was below the mean at entry were less likely to have a BP greater than 1 standard deviation (SD) above the mean at any of the examinations. Men with an entry BP greater than 1 SD above the mean were more likely to have BP greater than 1 SD above the mean later, but the relationship decreased considerably after 20 years, especially in 20-24-year age group. The results were similar for the probability of hypertension values (systolic BP greater than or equal to 140 or 150 mm Hg, diastolic BP greater than or equal to 90 or 95 mm Hg) at later examinations. Thus, BP in later life can be predicted from BP at ages 20-39 years and can identify groups at high or low risk for hypertension.