Objective: To assess the consistency of the benefits of blood pressure lowering on secondary stroke risk by age, sex and geographic region of recruitment.
Design: Randomized, placebo-controlled trial. Participants were randomized to the angiotensin-converting enzyme (ACE) inhibitor perindopril (plus the diuretic indapamide if not indicated or contraindicated) or to placebo(s) over a mean follow-up of 3.9 years. Main analyses used Cox proportional hazards models on an intention-to-treat basis. Subgroup results were standardized for the proportion (42%) taking single-drug therapy.
Setting: A total of 172 centres in Asia, Australia, New Zealand and Europe.
Participants: Patients (n = 6105) with a history of stroke or transient ischaemic attack, of whom 50% were aged over 65 years at baseline, 30% were women and 39% were from Asia.
Main outcome measures: Stroke, coronary heart disease and major vascular events.
Results: Overall, treatment reduced stroke by 28% [95% confidence interval (CI) 17-38%] and major vascular events by 26% (16-44%), with separately significant reductions across subgroups defined by age (< or > or = 65 years), sex and region (Asia or not). Treatment was safe and well tolerated, and the absolute benefits were large; 5 years' treatment would be expected to avert at least one major vascular event among every 20 patients in all age, sex and region subgroups. There was some evidence of particularly large benefits among younger participants and those from Asia.
Conclusions: Blood pressure lowering reduces secondary stroke risk, with large absolute benefits across groups defined by age, sex and geographic region.