Multiple trials have aimed to assess the effect of blood pressure control in the prehospital setting for patients with suspected acute stroke.  The INTERACT-4 trial was a multicenter, prospective, randomized, open-label, blind endpoint trial conducted in China, in which 2404 hypertensive patients with suspected acute stroke (based on FAST score >2, symptom onset <2h, SBP >150mmHg) were randomized to receive urapidil versus usual care in the prehospital setting. The primary outcome was modified Rankin score (mRs) distribution at 90 days. Overall, no significant difference in functional outcomes at 90 days were observed in the urapidil versus usual care groups (OR 1.00, 95% CI 0.87-1.15). However, when analyzed by stroke type, improved functional outcomes and lower rates of rebleeding were seen in patients with hemorrhagic stroke (46.5% of all enrolled patients), while worsened functional outcomes and mortality were seen in patients with ischemic stroke. These observations are consistent with standard practices of intensive blood pressure reduction in patients found to have ICH, versus the “permissive hypertension” approach to patients found to have cerebrovascular occlusion. The results of this trial are not practice-changing, but do highlight the importance of prompt stroke recognition, streamlined hospital workflows for expedited diagnostics (CT), and timely initiation of antihypertensive therapy in ICH patients. 

Bottom line: Prehospital blood pressure reduction was not shown to improve clinical outcomes in hypertensive patients suspected to have acute undifferentiated stroke.

References

Li, G., Lin, Y., Yang, J., Anderson, C. S., Chen, C., Liu, F., Billot, L., Li, Q., Chen, X., Liu, X., Ren, X., Zhang, C., Xu, P., Wu, L., Wang, F., Qiu, D., Jiang, M., Peng, Y., Li, C., Huang, Y., … INTERACT4 Investigators (2024). Intensive Ambulance-Delivered Blood-Pressure Reduction in Hyperacute Stroke. The New England Journal of Medicine, 390(20), 1862–1872. https://doi.org/10.1056/NEJMoa2314741