INTERACT2: a reason for optimism with spontaneous intracerebral hemorrhage?

Abstract

The first Intensive Blood Pressure Reduction in Acute Intracerebral Hemorrhage Trial (INTERACT1) study found that early intensive BP lowering seemed to attenuate haematoma growth when compared with a more conservative guideline based policy. Clinicians were therefore waiting with anticipation for the results of INTERACT2, in which 2839 patients with spontaneous ICH and a systolic BP between 150 and 220 mmHg were randomly assigned to receive intensive anti-hypertensive therapy with a systolic target of <140 mmHg within one hour, or a standard guideline recommended treatment of <180 mmHg. INTERACT2 failed to show a significant reduction in the rate of the primary outcome of death or major disability [modified Rankin scale score (mRS) of 3-6], with early intensive BP lowering. However, in the key secondary endpoint of an ordinal analysis of the distribution of mRS scores, there was a significant favorable shift in those patients with aggressive therapy. There were also more patients who were normal or near normal (mRS of 0-1) at 90 days. Reassuringly, there were no differences in the rate of death or numbers of serious adverse events between the two groups. INTERACT2 has shown that a strategy of early and aggressive BP lowering is safe in a wide range of clinical settings, and is probably effective. The Antihypertensive Treatment of Acute Cerebral Haemorrhage (ATACH) II trial, which is using similar BP targets to INTERACT, should shed further light on the benefit of early aggressive BP lowering in patients with spontaneous ICH.

Keywords: INTERACT2; blood pressure; haematoma expansion; intracerebral hemorrhage.