Comparison of visit-to-visit blood pressure variability and time in target range in predicting risk for cognitive outcomes in the SPRINT trial

Background Blood pressure (BP) variability (BPV) and time in target range (TTR) are emerging vascular risk factors for dementia, independent of traditionally targeted mean BP. Objective Determine whether BPV or TTR is most strongly associated with cognitive risk. Methods In this post hoc analysis of the SPRINT trial, 8034 participants underwent repeated BP measurement and cognitive testing at baseline and follow-up. Visit-to-visit BPV was calculated as average real variability. TTR was the percent of time in desired treatment arm target range (standard: 120-140 mmHg systolic BP; intensive: 110-130 mmHg systolic BP). Adjudicated clinical outcomes were no cognitive impairment, mild cognitive impairment (MCI), and probable dementia. We investigated a direct comparison of BPV and TTR in predicting cognitive risk, stratified by BP treatment group. Results Elevated BPV was associated with increased risk for MCI (adjusted HR: 1.21 [95% CI 1.10, 1.33], p < 0.001) and MCI/dementia (HR: 1.17 [95% CI 1.07, 1.27], p < 0.001) in the standard group, and dementia (HR: 1.17 [95% CI 1.01, 1.36], p = 0.039) in the intensive group. Higher TTR was related to lower dementia risk (HR: 0.72 [95% CI 0.60, 0.86], p < 0.001) in the intensive group only. Conclusions Visit-to-visit BPV outperformed TTR in predicting risk for MCI and MCI/dementia. TTR was more strongly associated with dementia risk under intensive treatment. Findings were independent of mean BP in a cohort with rigorously controlled BP and suggest newer aspects of BP control may be harnessed to further reduce cognitive risk. Clinical trial information ClinicalTrials.gov; NCT01206062.