Long-term systolic blood pressure time in target and risk of cardiovascular events in older adults: a secondary analysis of the ASPREE cohort

BACKGROUND: Blood pressure (BP) time in target range (TTR) predicts cardiovascular disease (CVD) in high-risk populations; however, TTR's predictive utility in older adults without prior CVD is uncertain. METHODS: We performed a post-hoc analysis of the ASPirin in Reducing Events in the Elderly trial and its observational follow-up. Systolic BP TTR for <140 and <130 mmHg was estimated for each participant using BPs from the first three visits. Participants with 0% or 100% TTR were categorized separately, and remaining participants grouped into tertiles using linear interpolation to estimate TTR. Cox proportional hazards models evaluated associations between TTR and adjudicated incident CVD and major adverse cardiovascular events (MACE) after the TTR estimation period, with 0% TTR as reference. RESULTS: Among 16,730 predominantly white Australian adults (mean age, 74 years) followed for a mean of 7.7 years after TTR estimation, 100% TTR <140 mmHg had reduced risk of CVD (HR, 0.81 [95% CI, 0.68-0.96]; P = .01), while 100% TTR <130 mmHg had reduced risks of CVD (HR, 0.82 [95% CI, 0.67-0.99]; P = .04) and MACE (HR, 0.72 [95% CI, 0.57-0.91]; P < .01). Associations were strongest among women, antihypertensive users, frail/pre-frail participants, and those younger than median age. Findings were consistent after adjusting for competing risk of non-CVD death, when the TTR estimation period was extended an additional year, and when estimated using proportion of individual visit BPs at target. CONCLUSIONS: Longer systolic BP TTR was associated with reduced risk of cardiovascular events in older adults, underscoring the importance of sustained BP control with aging.