Abstract
Abstract
Background and aims
Uncertainty persists over the effects of blood pressure (BP) lowering in acute stroke. The INTEnsive ambulance-delivered blood pressure Reduction in hyper-Acute stroke Trial (INTERACT4) aims to determine efficacy and safety of hyperacute intensive BP lowering in patients with suspected acute stroke. Given concerns over the safety of this treatment in the pre-hospital setting, particularly in relation to patients with intracerebral hemorrhage, we provide an update on progress of the study and profile of participants to date.
Methods
INTERACT4 is an ongoing multicentre, ambulance-delivered, randomized, open-label, blinded endpoint trial of pre-hospital BP lowering in patients with suspected acute stroke and elevated BP in China. Patients are randomized via a mobile phone digital system to intensive (target systolic BP [SBP] <140mmHg within 30 min) or guideline-recommended BP management. Primary outcome is an ordinal analysis of the full range of scores on the modified Rankin scale scores at 90 days.
Results
Between March 2020 and April 2023, 2053 patients (mean age 70 years, female 39%) were recruited with a mean BP 178/98 mmHg in whom 45% have a diagnosis of primary intracerebral hemorrhage upon arrival at hospital. At the time of presentation to hospital, the mean SBP was 160 and 170mmHg in the intensive and control groups (Δ10 mmHg), respectively. The independent data and safety monitoring board has not identified any safety concerns and recommended continuation of the trial. The sample size was reduced from 3116 to 2320 after meetings in August 2022 as the stroke mimic rate was persistently lower than initially estimated (6% vs 30%). The study is expected to be completed in late 2023 and the results announced in May 2024.
Conclusions
INTERACT4 is on track to provide reliable evidence of the effectiveness of ambulance-delivered intensive BP lowering in patients with suspected acute stroke.
Trial registration
ClinicalTrials.gov NCT03790800; registered on 2 January 2019. Chinese Trial Registry ChCTR1900020534, registered on 7 January 2019.
Funder
National Health and Medical Research Council (NHMRC) of Australia
a seed grant for research in under-served population of low-middle income countries from The George Institute For Global Health
Shanghai Key Clinical Discipline
Construction Project of Key Discipline Groups of Shanghai Pudong Health Bureau
Pilot Program of East Hospital
Stroke and dementia special fund of Shanghai Science and Technology Development Foundation
Clinical Plateau Discipline Construction Project of Shanghai Pudong New Area Health Committee
funding of the First Affiliated Hospital of Chengdu Medical College
the funding of Chengdu Medical College
the International Cooperation Project of Chengdu Science and Technology Bureau
the funding of Sichuan Science and Technology Program
Key R&D Project of Science & Technology Department of Sichuan Province
Takeda China
Publisher
Springer Science and Business Media LLC
Subject
Pharmacology (medical),Medicine (miscellaneous)