Heterogeneity of Stroke Pathophysiology and Neuroprotective Clinical Trial Design

Population heterogeneity alone may be sufficient to explain negative neuroprotective trials because even in the largest trials to date sample size is inadequate to detect effect size equivalent to those with thrombolysis, and it is possible that they have been severely underpowered. Reliable trials with inclusive entry criteria may be too large to be commercially feasible for novel compounds. Both sample size and total number of patients needing to be screened should be reduced by restricting entry to patients more likely to have a tissue target.