Early blood-pressure control not associated with improved outcomes in patients with undifferentiated stroke

1. In this randomized controlled trial, patients with stroke symptoms who were given antihypertensives en route to the hospital did not have superior outcomes compared to those whose blood pressure management was postponed until the hospital. 

2. Serious adverse events did not differ significantly between the two groups.

Evidence Rating Level: 1 (Excellent)

Study Rundown: Intracranial hemorrhage volume is one of the strongest predictors of functional outcomes after hemorrhagic stroke, which makes limiting hematoma expansion a critical treatment goal of standard bundled-care protocols. It is thought that blood pressure reduction specifically may help achieve this goal, but trials of blood pressure control alone have produced mixed results in both hemorrhagic and ischemic stroke. One possible explanation for the lack of consistent response is that blood pressure reduction may become increasingly ineffective as time elapses between symptom onset and treatment. This study, titled INTERACT4, was designed to evaluate the safety and efficacy of antihypertensive treatment within 2 hours of stroke onset and before hospital admission. Overall, it was found that functional outcomes at 90 days were similar between the intervention and usual-care groups. However, unplanned subgroup analysis revealed somewhat of a divergent effect according to stroke type. Treatment with antihypertensives appeared to be associated with lower odds of a poor functional outcome among patients with hemorrhagic stroke but higher odds of a poor functional outcome among patients with ischemic stroke. Neurological impairment scores were similar between groups at 24 hours as well as seven days, and serious adverse events occurred in just over one-quarter of both groups. The generalizability of these findings was limited by the heavy involvement of trained doctors in emergency services, the ethnically homogenous patient population, and the use of an antihypertensive agent that is not widely available internationally. Nonetheless, these results indicate that early, intensive blood-pressure reduction had no apparent benefit among patients with undifferentiated stroke.

Click here to read the study in NEJM

In-Depth [randomized controlled trial]: This open-label trial was conducted across 51 hospitals in China that utilized hospital-based or centralized ambulance services. Patients were eligible if they exhibited at least two stroke symptoms, one of which is an arm motor deficit and a systolic blood pressure>150 mmHg. A total of 2,425 adult patients were randomly assigned in a 1:1 ratio to receive either immediate blood-pressure reduction with intravenous urapidil targeting a systolic pressure of 130 to 140 mmHg or usual care. The primary outcome was functional status as assessed by the distribution of scores on the modified Rankin scale. The median time from symptom onset to randomization was 61 minutes, and the mean systolic blood pressure at randomization was 178 mmHg. Of all patients who had imaging-confirmed stroke, 1,041 cases (46.5%) were hemorrhagic, and 1199 (53.5%) were ischemic. The intervention and usual-care groups had similar functional outcomes at 90 days (odds ratio [OR] 1.00; 95% confidence interval [CI], 0.87 to 1.15). Among patients with hemorrhagic stroke, those in the intervention group had a lower likelihood of experiencing a poor functional outcome versus those in the control group (OR, 0.75; 95% CI, 0.60 to 0.92). Conversely, among patients with cerebral ischemia, those in the intervention group had a higher likelihood of experiencing a poor functional outcome compared to control (OR, 1.30; 95% CI, 1.06 to 1.60). Secondary outcomes such as disability, neurologic impairment, and mortality were similar between groups. Serious adverse events occurred in 27.5% of patients in the intervention group and 28.7% in the usual-care group. In summary, these results suggest that rapid, intensive blood pressure control may not be beneficial in the treatment of patients with undifferentiated stroke.

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