International Stroke Conference
January 24–26

Neal S. Parikh, MD

It was no surprise that the conference room assigned to this session was woefully inadequate in size. Stroke neurologists filled the seats, the carpet, and the aisles. The results of DEFUSE 3 and the updated acute ischemic stroke treatment guidelines had been released the prior day, and the world of acute stroke care had been changed. Stroke protocols, regional EMS triage protocols, and the entire systems of care require drastic changes to help us offer extended-window endovascular therapy to our patients.

In this session, we heard from leaders in the field. Raul Nogueira and Gregory Albers provided complementary information regarding the differences between their trials: DAWN and DEFUSE 3. The key differences pertain to the duration of the extended window, the stroke severity cut-off, ages of the patients included, and core sizes.  The key takeaway was that individuals in DEFUSE 3 who were DAWN-ineligible derived similar benefits from extended-window endovascular therapy as compared to DAWN-eligible patients. This suggests that, within the first 16 hours, the more forgiving DEFUSE 3 inclusion criteria can be applied. Further analyses comparing these trials will be forthcoming.

This session facilitated lively debate and optimistic speculation. The presenters mostly agreed that the observed effect sizes (number needed to treat of 2–3) are bad results. These large effect sizes suggest that other patients may benefit — that the inclusion criteria can be expanded. Tudor Jovin provocatively argued that advanced imaging is rate limiting for widespread implementation and may harm individuals by delaying therapy, especially among individuals with rapidly growing infarctions. His point is well taken: For these advances to be implemented in a lower resource setting, simplifying the inclusion criteria and protocols will be helpful.

The presenters argued that we will be able to extend the extended window to more stroke patients by reconsidering the need for advanced imaging, including individuals with larger core infarctions, and including individuals with moderate disability at baseline. With regards to advanced imaging, the presenters had conflicting opinions on the utility of non-contrast CT scans. In a particularly compelling slide, individuals with an ASPECTS score of 7 in DEFUSE 3 had core stroke volumes ranging from 0 to 100 cc!

I anticipate tremendous progress will occur in this realm in the next year, and I look forward to hearing about the stroke community’s solutions at ISC 2019.