INTEnsive ambulance-delivered blood pressure Reduction in hyper-ACute stroke Trial (INTERACT4): study protocol for a randomized controlled trial

Abstract

Background Early pre-hospital initiation of blood pressure (BP) lowering could improve outcomes for patients with acute stroke, by reducing hematoma expansion in intracerebral hemorrhage (ICH), and time to reperfusion treatment and risk of intracranial hemorrhage in ischemic stroke (IS). We present the design of the fourth INTEnsive ambulance-delivered blood pressure Reduction in hyper-ACute stroke Trial (INTERACT4). Methods A multi-center, ambulance-delivered, prospective, randomized, open-label, blinded endpoint (PROBE) assessed trial of pre-hospital BP lowering in 3116 hypertensive patients with suspected acute stroke at 50+ sites in China. Patients are randomized through a mobile phone digital system to intensive BP lowering to a target systolic BP of < 140 mmHg within 30 min, or guideline-recommended BP management according to local protocols. After the collection of in-hospital clinical and management data and 7-day outcomes, trained blinded assessors conduct telephone or face-to-face assessments of physical function and health-related quality of life in participants at 90 days. The primary outcome is the physical function on the modified Rankin scale at 90 days, analyzed as an ordinal outcome with 7 categories. The sample size was estimated to provide 90% power (α = 0.05) to detect a 22% reduction in the odds of a worse functional outcome using ordinal logistic regression. Discussion INTERACT4 is a pragmatic clinical trial to provide reliable evidence on the effectiveness and safety of ambulance-delivered hyperacute BP lowering in patients with suspected acute stroke. Trial registration ClinicalTrials.gov NCT03790800. Registered on 2 January 2019; Chinese Trial Registry ChiCTR1900020534. Registered on 7 January 2019. All items can be found in this protocol paper.

European Stroke Organisation (ESO) guidelines on mobile stroke units for prehospital stroke management

“…However, these results do not allow any overall conclusion as the information only comes from a very limited number of patients. Further research is needed to prove the potential clinical benefits of MSU treatment for ICH patients, and ongoing ICH treatment trials 80,81 , of which some are performed with MSU management 82 , will potentially open the field for additional therapeutic possibilities in the near future.…”

Blood Pressure Management After Intracerebral and Subarachnoid Hemorrhage: The Knowns and Known Unknowns

“…10 Thus, further data on the effects of ultra-early BP lowering are required, which is the basis of the ongoing the INTERACT4 (Intensive Ambulance-Delivered Blood Pressure Reduction in Hyper-Acute Stroke Trial; URL: https://www.clinicaltrials.gov; Unique identifier: NCT03790800). 28…”

Effects of intensive blood pressure lowering on cerebral ischaemia in thrombolysed patients: insights from the ENCHANTED trial

“…Moreover, we have been unable to provide recommendations over the optimal levels of blood pressure control in specific patient groups with acute ischaemic stroke. Further analysis of ENCHANTED2/MT, 4 and results of similar trials in patient who have received endovascular therapy and that of the ongoing Intensive Ambulance-delivered Blood Pressure Reduction in Hyper-Acute Stroke Trial (INTERACT4) 29 due in 2024, are expected to provide further insights into the effects of early intensive blood pressure lowering in different patient groups and clinical settings.…”