Nimodipine in traumatic subarachnoid haemorrhage: A re-analysis of the HIT I and HIT II trials

Two large randomised controlled trials have been performed to study the effect of the calcium antagonist nimodipine on the outcome of severe head injury, HIT I [1] amd HIT II [4]. Both trials showed a modest and statistically non-significant increase in the proportion of favourable outcomes in patients treated with nimodipine. A subgroup analysis of the HIT II trial [4, 5] suggested, however, that there could be a substantial protective effect of nimodipine in patients with traumatic subarachnoid haemorrhage (SAH). This report provides a re-analysis of the HIT I data to see whether it provides confirmatory evidence of the subgroup effect observed in HIT II, This involved performing a central review of the CT scans for the HIT I patients, to identify those individuals with evidence of traumatic SAH. The sample size was small, but the HIT I data gave no support to the hypothesis that nimodipine is protective in the traumatic SAH subgroup, where 69% of patients had a poor outcome on placebo and 74% of patients had a poor outcome on nimodipine. The data do not exclude the possibility of a clinically relevant beneficial effect of nimodipine in the traumatic SAH subgroup, but further data are required to provide a definitive answer.

In addition, we present a pooled analysis of the data from the two trials, which suggests that the overall benefit of treating unselected head injured patients with nimodipine is unlikely to be clinically relevant.