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

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.