Intensive versus standard blood pressure control in type 2 diabetes: a restricted mean survival time analysis of a randomised controlled trial

Abstract

Background Restricted mean survival time analysis offers an intuitive and robust summary of treatment effect compared with HRs.Objective To examine the effect of intensive versus standard blood pressure (BP) control on death or cardiovascular events in type 2 diabetes.Design Secondary analysis of the Action to Control Cardiovascular Risk in Diabetes Blood Pressure trial.Setting 77 sites in the USA and Canada.Participants 4733 adults with type 2 diabetes at high risk for cardiovascular events.Interventions Systolic BP target <120 mm Hg (n=2371) versus <140 mm Hg (n=2362).Measurements Composite endpoint of death, non-fatal myocardial infarction or non-fatal stroke.Results The mean event-free survival time over 5 years (1825 days) was similar between intensive and standard BP control (1716 vs 1714 days; mean difference, 1.3 (95% CI −18.1 to 20.7) days). However, intensive BP treatment was more beneficial for those assigned to standard glycaemic control (1725 vs 1697 days; mean difference, 28.1 (95% CI 0.4 to 55.9) days), but not for those assigned to intensive glycaemic control (1706 vs 1731 days; mean difference, −25.2 (95% CI −52.3 to 1.9) days) (p=0.008 for interaction). In subgroup analysis, the mean event-free survival time difference between intensive and standard BP treatment was −76.0 (95% CI –131.8 to –20.3) days for those with cognitive impairment and 21.8 (95% CI −24.0 to 67.5) days for those with normal cognitive function (p=0.008 for interaction). The effect was not different by age, sex and baseline cardiovascular disease status.Conclusions Intensive BP treatment may reduce death and cardiovascular events among patients with type 2 diabetes receiving standard glycaemic treatment and without cognitive impairment.Trial registration number NCT00000620; Post-results.