To assess the benefits of blood pressure (BP) lowering on vascular events separately for Asian and for Western participants with particular emphasis on stroke subtypes and cardiac outcomes.
This is a subsidiary analysis of Perindopril Protection Against Recurrent Stroke Study (PROGRESS), a randomized, placebo-controlled trial that established the benefits of BP lowering in 6105 patients with cerebrovascular disease, randomly assigned to either active treatment (perindopril for all, and indapamide for those with neither an indication for, nor a contraindication to, a diuretic) or placebo(s). Outcomes are total and cause-specific vascular outcomes.
The annual rates for total major vascular events were 4.2% in Asian and 5.2% in Western participants. Overall stroke rates were greater in Asian compared to Western participants with proportionally more lacunar infarctions and haemorrhagic strokes in Asians and more cardio-embolic infarctions and large artery infarctions in Western participants. Active treatment reduced BP by 10.3/4.6 mmHg in Asian, and by 8.1/3.6 mmHg in Western participants. Among Asian participants there was a 38% [95% confidence interval (CI) 23–49%] reduction in major vascular events compared to a 20% (95% CI 7–31%) reduction in Western participants (P homogeneity = 0.06). Similarly, there were higher relative risk reductions for all other outcomes among Asian participants, but this only reached statistical significance for heart failure and vascular death (P = 0.02 for each). The number needed to treat for major vascular events over 5 years was 15 (95% CI 10–26) in Asian compared to 28 (95% CI 17–94) in Western participants (P homogeneity = 0.09).
BP lowering reduces the risk of major vascular events, with separately significant reductions, in both Asia and the West.