Systolic Blood Pressure Trajectories in the Acute Phase and Clinical Outcomes in Two-year Follow-up among Patients with Ischemic Stroke.

Background: Optimal blood pressure (BP) levels during acute ischemic stroke have not been established. We studied associations between systolic BP trajectories during acute phase and subsequent clinical outcomes among patients with ischemic stroke.

Methods: 4,036 patients with acute ischemic stroke and elevated BP from the CATIS trial were included in this analysis. Three BPs were measured every 2 hours in day 1, every 4 hours during days 2 and 3, and every 8 hours thereafter until hospital discharge or death. Clinical outcomes were assessed at 3, 12 and 24 months. Latent variable mixture modeling was used to identify subgroups that share a similar underlying trajectory of systolic BP during the first seven days after stroke onset. Logistic regression and Cox proportional hazards models were used to examine the associations between systolic BP trajectories and clinical outcomes during follow-up.

Results: We identified five systolic BP trajectories of high, high-to-moderate-low, moderate-high, moderate-low, and low. Compared to participants in high trajectory, multiple-adjusted odds ratios (95% confidence interval) of all-cause mortality at 3 months for individuals in high-to-moderate-low, moderate-high, moderate-low, and low were 0.34 (0.15-0.77), 0.58 (0.32-1.04), 0.29 (0.15-0.56), and 0.56 (0.26-1.19), respectively. Likewise, the corresponding hazard ratios for all-cause mortality in 24 months were 0.66 (0.44-1.00), 0.74 (0.53-1.05), 0.45 (0.32-0.66), and 0.61 (0.40-0.93), respectively. Similar associations were observed for recurrent stroke and cardiovascular disease, and in both the intervention and control groups.

Conclusion: Patients with moderate-low systolic BP during acute ischemic stroke had a lower risk of adverse clinical outcomes.