Blood pressure reduction for the secondary prevention of stroke: a Chinese trial and a systematic review of the literature

Abstract

We assessed, in a double-blind, placebo-controlled trial, whether lowering blood pressure (BP) prevents the recurrence of stroke in Chinese patients with cerebrovascular disease. Patients were randomized into two groups: 2825 patients received a placebo and 2840 patients received 2.5 mg of indapamide daily. The primary and secondary outcomes were the recurrence of fatal or nonfatal stroke and major fatal and nonfatal cardiovascular events, respectively. The average systolic/diastolic BP at randomization was 153.8/92.8 mm Hg. At median follow-up (2 years), BP was, on an average, 6.8/3.3 mm Hg lower in patients on active treatment. In total, 143 patients on indapamide and 219 patients on placebo had recurrent strokes (hazard ratio for indapamide, 0.69; 95% confidence interval (CI): 0.54-0.89; P<0.001). In addition, 199 patients on indapamide and 258 patients on placebo had a cardiovascular event (hazard ratio, 0.75; 95% CI: 0.89-0.62; P=0.002). We performed a systematic review of literature that included our new results. Across 10 trials, the odds ratio for the prevention of stroke recurrence by BP lowering was 0.78 (95% CI: 0.68-0.90; P=0.0007). The pooled odds ratio was 0.63 (95% CI: 0.54-0.73; P<0.0001) for trials involving diuretics as a component of therapy and 0.93 (95% CI: 0.87-1.01; P=0.086) for trials in which treatment included renin system inhibitors (P<0.0001 for heterogeneity). The weighted correlation between the odds for stroke recurrence and the reduction in systolic BP was -0.57 (P=0.067). In conclusion, BP lowering by indapamide treatment reduced the recurrence of stroke and the incidence of cardiovascular events in Chinese patients with cerebrovascular disease. Whether prevention of stroke recurrence depends on drug class, degree of BP lowering or both requires further investigation.