INTERACT 2 results just presented in London
Blogging Live from the European Stroke Conference:
The second intensive blood pressure reduction in acute cerebral hemorrhage trial (INTERACT 2) results were just presented at the European Stroke Conference and are to be published in the New England Journal of Medicine later today. This is the definitive phase 3 clinical trial of early aggressive BP goal (goal systolic BP <140) vs. more conservative control (goal systolic BP <180) in patients with intracerebral hemorrhage (ICH) on CT presenting less than 6 hours from symptom onset.
Over 4 years a total of 2839 patients were randomized an average of 3.8 hours after symptom onset, over 2/3rd of cases were from China, the vast majority had deep hemorrhages with about 1/3rd having intraventricular hemorrhage as well. Overall about 12% died, equal in the two groups. The primary of death or disability was seen in 52% of aggressive vs 55%of conservative treatment groups OR 0.87, p=0.06. When performing the ordinal shift analysis there was a significant wit a 13% improvement.
This study going to change practice and early aggressive lowering of blood pressure in hypertensive ICH is going to be the norm. The first INTERACT study demonstrated that early aggressive BP reduced hemorrhage expansion and that this effect was most potent when treatment was initiated earlier. The results of INTERACT 2 further validate the concept of early aggressive therapy demonstrating a consistent benefit despite the near miss for significance to a p-values less than 0.05. This may lead to some skepticism about the result, but it should be noted that the standard treatment arm also received early antihypertensive therapy, albeit in lower doses.
Of interest time from onset of symptoms to recruitment did not have an effect on outcome in INTERACT 2. This was surprising as we would have expected earlier treatment to be better. It was reassuring that aggressive treatment led to no increase in neurological deterioration. The treatment effect of early aggressive therapy was around 4% was less than the expected 7%.
Although there is cause for excitement in the realm of ICH therapy, the results of the INTERACT 2 study beg the question: what is next? How can we improve on these results and get even better outcomes for patients with ICH. Could there be some forms of combination therapies, or earlier treatment which would be even better? For the time being aggressive urgent BP lowering in hypertensive ICH makes sense.