Association of long-term time in target range for systolic blood pressure with cardiovascular risk in the elderly: a Chinese veteran cohort study.

Abstract

Short-term blood pressure (BP) time in target range (TTR) independently predicts cardiovascular (CV) outcomes in adults. However, there are limited data regarding long-term TTR for BP among elderly participants. We aimed to determine whether future CV risk varies for those who can maintain a long-term systolic BP (SBP) target range by assessing TTR in elderly individuals with hypertension. The Chinese veteran cohort study included 943 elderly participants with hypertension aged over 75 years. The primary outcome was the first occurrence of CV events during annual visits. Time in target range was estimated over 15 years of follow-up using linear interpolation. The target range was defined as 120-140 mmHg according to guidelines. The association between SBP TTR and CV outcomes was estimated using multivariable Cox proportional hazards models. During the 15 year follow-up, the probability of CV events gradually decreased with increasing TTR for SBP. After multivariable adjustment for traditional CV risk factors and mean BP, comparing the highest vs. lowest quartiles of TTR for SBP, the hazard ratios (HRs) [95% confidence intervals (CIs)] were 0.424 (0.289-0.624) for the primary outcome. For each 1 SD increase in TTR, the risk of the primary outcome decreased by 25.4% (HR: 0.746; 95% CI: 0.666-0.834). Consistent findings were observed in sensitivity analyses. Greater long-term TTR for SBP was associated with a decreased risk of CV events in elderly individuals independent of mean BP, suggesting that SBP TTR might serve as a modifiable risk factor for future CV health in elderly patients with hypertension. This ongoing Chinese veteran cohort study adds to the understanding of the relationship between higher long-term systolic blood pressure (SBP) time in target range (TTR) and cardiovascular benefits among elderly individuals with hypertension.