Initial systolic blood pressure, antihypertensive treatment timing and outcomes in acute ischemic stroke: a subgroup analysis of CATIS-2 trial

Objective: Whether initial systolic blood pressure (SBP) influences blood pressure management in acute ischemic stroke (AIS) and its association with outcome remains inconclusive. We conducted a subgroup analysis of CATIS-2 trial (China Antihypertensive Trial in Acute Ischemic Stroke II) to assess the impact of early vs. delayed antihypertensive treatment in AIS, stratified by baseline SBP. Methods: CATIS-2 was a multicenter, randomized trial enrolling AIS patients within 24–48 h after onset, presenting with SBP 140–219 mmHg and without reperfusion therapy. Participants were randomized to receive immediate antihypertensive treatment or delayed treatment initiated on day 8. The primary outcome was functional dependency or death (modified Rankin Scale score ≥3) at 90-day. Three prespecified baseline SBP subgroups (<160, 160–179, and ≥180 mm Hg) were analyzed. Results: 4802 patients (mean age 63.7 years, 65.0% male) were included, with baseline SBP < 160 mmHg ( n = 2233), 160–179 mmHg ( n = 1849), and ≥180 mmHg ( n = 720). Among patients with baseline SBP 160–179 mmHg, early antihypertensive treatment was associated with increased risk of primary outcome compared to delayed treatment [13.3% vs. 10.4%; odds ratio (OR) 1.32, 95% confidence interval (CI) 1.00–1.76]. This finding was not observed in the baseline SBP < 160 mmHg subgroup (OR 1.12, 95% CI 0.84–1.50) or ≥180 mmHg subgroup (OR 0.98, 95% CI 0.66–1.46). No significant differences were found in stroke recurrence or major vascular events between treatment strategies across SBP subgroups. Conclusion: Early antihypertensive treatment may increase the risk of functional dependency or death in AIS patients with moderately elevated baseline SBP. These findings provide valuable insights into clinical practice regarding individualized blood pressure management in AIS. Further research is warranted. Registration: ClinicalTrials.gov (NCT03479554)