Early antihypertensive treatment and clinical outcomes in acute ischemic stroke: subgroup analysis by baseline blood pressure

Background:We studied the effect of early antihypertensive treatment on death, major disability, and vascular events among patients with acute ischemic stroke according to their baseline SBP.Methods:We randomly assigned 4071 acute ischemic stroke patients with SBP between 140 and less than 220mmHg to receive antihypertensive treatment or to discontinue all antihypertensive medications during hospitalization. A composite primary outcome of death and major disability and secondary outcomes were compared between treatment and control stratified by baseline SBP levels of less than 160, 160-179, and at least 180mmHg.Results:At 24h after randomization, differences in SBP reductions were 8.8, 8.6 and 7.8mmHg between the antihypertensive treatment and control groups among patients with baseline SBP less than 160, 160-179, and at least 180mmHg, respectively (P<0.001 among subgroups). At day 14 or hospital discharge, the primary and secondary outcomes were not significantly different between the treatment and control groups among subgroups. However, there was a significant interaction between antihypertensive treatment and baseline SBP subgroups on death (P=0.02): odds ratio (95% CI) of 2.42 (0.74-7.89) in patients with baseline SBP less than 60mmHg and 0.34 (0.11-1.09) in those with baseline SBP at least 180mmHg. At the 3-month follow-up, the primary and secondary clinical outcomes were not significantly different between the treatment and control groups by baseline SBP levels.Conclusion:Early antihypertensive treatment had a neutral effect on clinical outcomes among acute ischemic stroke patients with various baseline SBP levels. Future clinical trials are warranted to test BP-lowering effects in acute ischemic stroke patients by baseline SBP levels.Trial Registration:ClinicalTrials.gov Identifier: NCT01840072.