[The second (main) phase of an open, randomised, multicentre study to investigate the effectiveness of an INTEnsive blood pressure Reduction in Acute Cerebral hemorrhage Trial (INTERACT2): protocol and baseline characteristics of patients included in France]

Abstract

Rationale and aim: The INTERACT pilot study demonstrated the feasibility of the protocol, safety of early intensive blood pressure (BP) lowering, and effects on hematoma expansion within 6hours of onset of intracerebral hemorrhage (ICH). This article describes the design of the second, main phase, INTERACT2. INTERACT2 aims to compare the effects of a management strategy of early intensive BP lowering with a more conservative guideline-based BP management policy in patients with acute ICH. This article also compares the baseline characteristics of the patients included in France with the baseline characteristics of the patients included in the pilot study INTERACT1.

Design of the study: INTERACT2 is an international, prospective, multicentre, open, assessor-blinded outcome (PROBE), randomised, controlled trial. Patients with a systolic BP greater than 150mmHg are centrally randomised to either to an intensive BP lowering treatment (Systolic BP≤140mmHg within 1hour) or to a conservative treatment strategy (target systolic BP of 180mmHg). A projected 2800 subjects are to be enrolled from approximately 140 centres worldwide to provide 90% power (α 0.05) to detect a beneficial effect of early treatment on the primary outcome.

Study outcomes: The primary outcome is the combined endpoint of death and dependency according to the modified Rankin Scale (mRS) at 90 days. The key secondary outcome is the primary endpoint in those patients treated within 4hours of ICH. Other predefined secondary outcomes are the separate components of the primary endpoint, grades of physical function on the mRS, health-related quality of life on the EuroQoL, recurrent stroke and other vascular events, days of hospitalisation, requirement for permanent residential care, and unexpected serious adverse events. The study is registered under NCT00716079, ISRCTN73916115, and ACTRN12608000362392.

Population: As of early July, 152 patients have been included in France. When compared with the patients randomised in the INTERACT1 pilot study, these patients are older, less likely to have had a previous ICH, more often on antiplatelet or warfarin therapy, have a lower diastolic BP, arere more severe clinically (higher NIHSS) and experience their first ICH.