Long-term systolic blood pressure and cardiovascular risks among patients with ischemic stroke: a register-based cohort study

Background: The impact of blood pressure fluctuations on the prognosis of stroke has been well documented, but little is known about the association between long-term systolic blood pressure (SBP) levels and the risks of cardiovascular outcomes in patients with ischemic stroke (IS). Methods: In this retrospective cohort study, we included a total of 11 357 eligible IS patients hospitalised in Shenzhen, China between 1 July 2017 and 1 October 2023. One-year levels of SBP after IS patient discharge were identified using group-based trajectory models (GBTM). Propensity score-overlap weighted Cox regression models were used to assess the associations between SBP levels and the risks of recurrent stroke and major adverse cardiovascular events (MACE; including recurrent stroke, ischemic heart disease, and heart failure) within a 36-month follow-up period, respectively. Furthermore, we quantitatively assessed the benefits potentially gained from optimal SBP levels by calculating age-scale restricted mean survival times. Results: Three one-year GBTM-derived SBP level patterns were identified: normal (n = 2120), high-normal (n = 7949), and uncontrolled SBP (n = 1288). During a median follow-up of 1.75 years, IS patients with normal and high-normal SBP were associated with lower risks of recurrent stroke or MACE, with weighted hazard ratios (95% confidence interval (CI)) ranging from 0.68 (95% CI = 0.54-0.86) to 0.89 (95% CI = 0.78-1.02), compared to those with uncontrolled SBP. Furthermore, IS patients aged 45 to 70 years with normal or high-normal SBP may derive greater health benefits, with the event-free survival time ranging from 7.12 to 0.27 years. Conclusions: Maintaining sustained normal or high-normal SBP levels one year after discharge may be associated with a reduced risk of adverse cardiovascular events and potentially yields greater health benefits for IS patients.