Abstract 204: Blood Pressure Reduction And Stroke Recurrence: The Progress Trial

Abstract

Background: A recent observational analysis of a large-scale randomized controlled trial identified a “J-curve” phenomenon such that low and high blood pressure (BP) levels are associated with increased risks of recurrent stroke among patients with recent ischemic stroke. The objective of the present analysis was to determine whether larger reduction in BP associated with treatment increases the risks of recurrent stroke among patients with cerebrovascular disease. Methods: This is a subsidiary analysis of the PROGRESS trial, a randomized, placebo-controlled trial that established the beneficial effects of BP lowering in secondary prevention of stroke. A total of 6105 patients with prior stroke or transient ischemic attack were randomly assigned to either active treatment (perindopril ± indapamide) or matching placebo(s). There were no BP criteria for entry. BP was measured at every visit and groups of participants defined by reduction in systolic BP (SBP) from baseline (<0, 0-9, 10-19 and ≧20 mm Hg) were used for these analyses. Outcomes of the present analyses were recurrent hemorrhagic and ischemic stroke. Results: During a mean follow-up of 3.9 years, 111 hemorrhagic stroke and 565 ischemic stroke events were observed. There were clear inverse associations between SBP reduction and the risk of hemorrhagic stroke even after adjustment for age, sex, region, baseline SBP, diabetes, current smoking and randomized treatment: adjusted annual incidence rates were 0.08%, 0.06%, 0.05% and 0.03% for participant groups defined by reduction in SBP levels of <0, 0-9, 10-19 and ≧20 mm Hg, respectively. The lowest risks of hemorrhagic stroke were observed among patients who achieved ≧20 mm Hg reduction in SBP associated with treatment. Annual incidence of ischemic stroke was 2.19%, 1.74%, 1.73% and 1.72% for the same participant groups. Compared with patients who did not achieve any SBP reduction, the decreases in the risk of ischemic stroke were similar in the groups achieving SBP reductions of 0-9, 10-19 and ≧20 mm Hg. Conclusions: The present analysis provided no evidence of increase in recurrent stroke associated with larger reduction in SBP produced by BP lowering treatment among patients with cerebrovascular disease.