Control of Blood Pressure and Risk of Stroke Among Pharmacologically Treated Hypertensive Patients

Abstract

Background and Purpose-Despite improved control of blood pressure during the last decades in the United States, a considerable proportion of treated hypertensives have not achieved target blood pressure levels. We estimated the proportion of strokes occurring among treated hypertensive patients that may be attributable to uncontrolled blood pressure. Methods-A population-based case-control study was conducted among treated hypertensive members of Group Health Cooperative of Puget Sound. Cases were treated hypertensive patients who sustained a first fatal or nonfatal, ischemic (nϭ460) or hemorrhagic (nϭ95) stroke during 1989 -1996. Controls were a random sample of stroke-free, treated hypertensive Group Health Cooperative enrollees (nϭ2966), similar in age to the stroke cases. Multiple measurements of blood pressure and other cardiovascular risk factors were collected from medical records. Logistic regression was used to estimate the risk of ischemic stroke and hemorrhagic stroke associated with uncontrolled blood pressure, defined as diastolic blood pressure Ͼ90 mm Hg or systolic blood pressure Ͼ140 mm Hg. The fraction of strokes attributable to uncontrolled blood pressure among treated hypertensives was calculated. Results-Blood pressure was uncontrolled in 78% of ischemic stroke cases, 85% of hemorrhagic stroke cases, and 65% of controls. After adjustment for potential confounders, uncontrolled blood pressure among treated hypertensive patients was moderately associated with ischemic stroke (risk ratioϭ1.5 [95% CI, 1.2 to 1.9]) and strongly related to hemorrhagic stroke (risk ratioϭ3.0 [95% CI, 1.7 to 5.4]). We estimated that 27% (95% CI, 11% to 39%) of the ischemic strokes and 57% (95% CI, 26% to 75%) of the hemorrhagic strokes among treated hypertensive patients were attributable to uncontrolled blood pressure. Overall, 32% (95% CI, 14% to 45%) of all strokes were attributable to uncontrolled blood pressure. Conclusions-A considerable proportion of incident strokes among treated hypertensive patients may be prevented by achieving control of blood pressure. (Stroke. 2000;31:420-424.)

Blood Pressure Control and Risk of Stroke

“…Those observations are consistent with other publications. 2,6,14 The findings of this study indicate that the traditional "rule of halves" is still valid. This may be one reason why the incidence of stroke in Sweden has remained unaltered or tended to increase.…”

“…Few population-based studies have studied the incidence of stroke in relation to the quality of hypertension treatment. 5,6 The aim of the present population-based study is to evaluate the relationship between the incidence of first-ever stroke and the quality of BP control in Swedish men and women with treatment for hypertension. An attempt was also made to explore whether the quality of BP control was related to the patient's socio-demographic characteristics, lifestyle, and health-related problems.…”

Aldosterone synthase gene (CYP11B2) promoter polymorphism as a risk factor for ischaemic stroke in Tunisian Arabs

“…5,6 These include coagulation, inflammatory, and the renin-angiotensin-aldosterone system (RAAS) genes. 4,7 The RAAS is a hormone system that regulates systemic blood pressure, salt and water homeostasis, via the activity of angiotensin II, 8,9 and increased RAAS activity has been linked with an increased risk of myocardial infarction and stroke. 10,11 In addition to angiotensin II, aldosterone is an important component of the RAAS, and plays an important role in controlling blood pressure, and water and electrolyte homeostasis.…”

Orthostatic Hypotension as a Risk Factor for Stroke

“…5,6 Identifying modifiable risk factors is therefore important, and clinical studies have suggested that orthostatic hypotension (OH) could be such a risk factor. [7][8][9][10][11] However, while numerous studies have documented the effects of BP and hypertension [12][13][14][15][16] and use of antihypertensive medication [17][18][19][20] on stroke, few epidemiological studies have evaluated OH as a risk factor for stroke. 11 In cross-sectional studies, postural hypotension was associated with cerebrovascular disease, neurological symptoms, and/or transient ischemic attacks.…”