Intensive Ambulance-Delivered Blood-Pressure Reduction in Hyperacute Stroke

Gang Li, Yapeng Lin, Jie Yang, Craig S Anderson, Chen Chen, Feifeng Liu, Laurent Billot, Qiang Li, Xiaoying Chen, Xiaoqiu Liu, Xinwen Ren, Chunfang Zhang, Ping Xu, Lijun Wu, Feng Wang, Daijun Qiu, Mei Jiang, Yiqian Peng, Chaohui Li, Yiyang Huang, Xiaohui Zhao, Jiye Liang, Yao Wang, Xiangjun Wu, Xiaoyun Xu, Guofang Chen, Dongya Huang, Yue Zhang, Lian Zuo, Guozhao Ma, Yumei Yang, Junjie Hao, Xiahong Xu, Xinli Xiong, Yueyu Tang, Yijia Guo, Jianping Yu, Shuping Li, Song He , Fengkai Mao, Quandan Tan, Song Tan, Nengwei Yu, Ruxiang Xu, Mingwei Sun, Binghu Li, Jiang Guo, Leibo Liu, Hueiming Liu, Menglu Ouyang, Lei Si 1, Hisatomi Arima, Philip M Bath, Gary A Ford, Thompson Robinson, Else Charlotte Sandset, Jeffrey L Saver, Nikola Sprigg, H Bart van der Worp, Lili Song; INTERACT4 investigators; INTERACT4 Investigators

BACKGROUND

Treatment of acute stroke, before a distinction can be made between ischemic and hemorrhagic types, is challenging. Whether very early blood-pressure control in the ambulance improves outcomes among patients with undifferentiated acute stroke is uncertain.

METHODS

We randomly assigned patients with suspected acute stroke that caused a motor deficit and with elevated systolic blood pressure (≥150 mm Hg), who were assessed in the ambulance within 2 hours after the onset of symptoms, to receive immediate treatment to lower the systolic blood pressure (target range, 130 to 140 mm Hg) (intervention group) or usual blood-pressure management (usual-care group). The primary efficacy outcome was functional status as assessed by the score on the modified Rankin scale (range, 0 [no symptoms] to 6 [death]) at 90 days after randomization. The primary safety outcome was any serious adverse event.

RESULTS

A total of 2404 patients (mean age, 70 years) in China underwent randomization and provided consent for the trial: 1205 in the intervention group and 1199 in the usual-care group. The median time between symptom onset and randomization was 61 minutes (interquartile range, 41 to 93), and the mean blood pressure at randomization was 178/98 mm Hg. Stroke was subsequently confirmed by imaging in 2240 patients, of whom 1041 (46.5%) had a hemorrhagic stroke. At the time of patients’ arrival at the hospital, the mean systolic blood pressure in the intervention group was 159 mm Hg, as compared with 170 mm Hg in the usual-care group. Overall, there was no difference in functional outcome between the two groups (common odds ratio, 1.00; 95% confidence interval [CI], 0.87 to 1.15), and the incidence of serious adverse events was similar in the two groups. Prehospital reduction of blood pressure was associated with a decrease in the odds of a poor functional outcome among patients with hemorrhagic stroke (common odds ratio, 0.75; 95% CI, 0.60 to 0.92) but an increase among patients with cerebral ischemia (common odds ratio, 1.30; 95% CI, 1.06 to 1.60).

CONCLUSIONS

In this trial, prehospital blood-pressure reduction did not improve functional outcomes in a cohort of patients with undifferentiated acute stroke, of whom 46.5% subsequently received a diagnosis of hemorrhagic stroke. (Funded by the National Health and Medical Research Council of Australia and others; INTERACT4 ClinicalTrials.gov number, NCT03790800; Chinese Trial Registry number, ChiCTR1900020534.).