Review, Historical Context, and Clarifications of the NINDS rt-PA Stroke Trials Exclusion Criteria
Diogo C. Haussen, MD
A rapidly improving stroke symptom (RISS) is a commonly encountered clinical scenario, which is inherently associated with doubts regarding the possibility of intravenous alteplase (IV t-PA) use. Some patients improve substantially, but partially, and remain with important clinical deficits if untreated. Others recover to a state with minimal deficits, where the risk of IV t-PA would potentially generate a devastating hemorrhagic complication. Therefore, the operationalization of the RISS concept is important in order to maximize the utilization of thrombolysis while maintaining an acceptable risk-benefit ratio.
The TREAT Task Force provides the readers of Stroke with an insightful and practical report. The authors review the historical context and intent of the original investigators underlying the exclusion of RISS on the NINDS trial and develop a useful and clinically meaningful definition.
The authors clarify that the original intention in using “RISS” as a contraindication on the NINDS trial was to avoid the unnecessary treatment of TIAs. With this in mind, the conclusion is straightforward: the definition of RISS should be reserved for those who improve to a non-disabling deficit. One should treat a patient that, despite improving, still has a potentially disabling deficit.
Moreover, the authors reinforce that delays in administering the thrombolytic is unacceptable (monitoring may be performed solely while preparing and administering the drug). Importantly, the role of imaging in establishing tissue at risk (either through vascular imaging or perfusion maps) despite a non-disabling deficit is described as a totally different and much more complex matter.