Risk of stroke in relation to level of blood pressure and other risk factors in treated hypertensive patients

Background and Purpose-Treatment of hypertension effectively reduces the ri sk of stroke. However, many treated patients still have high blood pressure (BP), other cardiovascular risk factors, and complications. The risk of st roke in treated hypertensive patients is not well understood. Methods-We analyzed the level of BP over 1 year before the onset; of stroke and other cardiovascular risk factors in treated hypertensive patients in a case-control study. The study population included 126 hypertensive patien ts (74 men; mean age, 70.9 years) with first strokes during 1988-1993 who h ad been treated for >1 year before stroke onset (stroke group). As a contro l group, we selected 126 sex- and age-matched hypertensive patients who wer e treated during the same period and were free from stroke. Results-Mean 12-month BP was not significantly different between stroke and control groups, although systolic BP was 2.5 mm Hg higher in the stroke gr oup (148.7 [95% CI, 146.1 to 151.3]/82.1 [95% CI, 80.5 to 83.71 versus 146. 2 [95% CI, 143.8 to 148.6]/82.4 [95% CI, 81.0 to 83.8] mm Hg). In patients aged <70 years, mean systolic BP was significantly higher in the stroke gro up than the control group (150.5 [146.3 to 154.71 versus 144.0(140.6 to 147 .4) mm Hg), Mean pulse pressure was also significantly higher in the stroke group than the control group in patients aged <70 years but not in older p atients. In the stroke group, the level of BP within 1 month before stroke onset did not differ from the mean value over the 12-month period. Patients with brain hemorrhage had higher diastolic BP than those with other subtyp es. The stroke group had higher plasma glucose, lower HDL cholesterol, and higher frequencies of diabetes mellitus, proteinuria, atrial fibrillation ( 29.4% versus 4.0%), and use of antiplatelet (31.0% versus 11.1%) and antico agulant (10.3% versus 1.6%) agents than the control group. Conclusions-The onset of stroke in treated hypertensive patients was relate d to a higher-level of BP in subjects <70 years old, although this relation ship was not obvious in older patients. The risk of stroke in these patient s was associated with the presence of metabolic risk factors and cardiovasc ular complications. Office BP did not change significantly 1 month before t he onset of stroke.