Elevated midlife blood pressure increases stroke risk in elderly persons -The framingham study

Background: Stroke risk predictions are traditionally based on current bloo d pressure (13P). The potential impact of a subject's past BP experience (a ntecedent BP) is unknown. We assessed the incremental impact of antecedent BP on the risk of ischemic stroke. Methods: A total of 5197 stroke-free subjects (2330 men) in the community-b ased Framingham Study cohort were enrolled from September 29, 1948, to Apri l 25, 1953, and followed up to December 31, 1998. We determined the 10-year risk of completed initial ischemic stroke for 60-, 70-, and 80-year-old su bjects as a function of their current BP (at baseline), recent antecedent B P (average of readings at biennial examinations 1-9 years before baseline), and remote antecedent BP (average at biennial examinations 10-19 years ear lier), with adjustment for smoking and diabetes mellitus. Models incorporat ing antecedent BP were also adjusted for baseline BP. The effect of each BP component (systolic 13P, diastolic BP, and pulse pressure) was assessed se parately. Results: Four hundred ninety-one ischemic strokes (209 in men) were observe d in eligible subjects. The antecedent BP influenced the 10-year stroke ris k at the age of 60 years (relative risk per SD increment of recent antecede nt systolic BP: women, 1.68 [95% confidence interval, 1.25-2.25]; and men, 1.92 [95% confidence interval, 1.39-2.66]) and at the age of 70 years (rela tive risk per SD increment of recent antecedent systolic BP: women, 1.66 [9 5% confidence interval, 1.28-2.14]; and men, 1.30 [95% confidence interval, 0.97-1.75]). This effect was evident for recent and remote antecedent BP, consistent in hypertensive and nonhypertensive subjects, and demonstrable f or all BP components. Conclusions: Antecedent BP contributes to the future risk of ischemic strok e. Optimal prevention of late-life stroke will likely require control of mi dlife BP.