Thrombolysis with alteplase 3-4.5 hours after acute ischaemic stroke: trial reanalysis adjusted for baseline imbalances

We congratulate Alper et al for their reanalysis of the Third European Cooperative Acute Stroke Study.1 They found that after adjusting for baseline imbalances in history of prior stroke and stroke severity, there was no statistical benefit with alteplase, but the harms were reconfirmed. So, the difference in outcome could be fully explained by the baseline imbalance. It is worth remembering that a clinical trial has internal validity if and only if the imbalance between groups, bias in the assessment of outcome, and chance have been excluded as possible explanations for the difference in outcomes. It also reaffirms the fragility of this evidence base,2 and the importance of replication studies, something that has not been achieved on this subject. Indeed, the Third International Stroke Trial, the largest clinical trial on this subject that enrolled patients up to 6 hours after stroke onset, failed to demonstrate benefit...
Source: Evidence-Based Medicine - Category: Internal Medicine Authors: Tags: Letters Source Type: research