Platform Presentation The Joint Annual Meeting of the Stroke Society of Australasia (SSA) and Smartstrokes 2023

Early Reperfusion after Pre-hospital Thrombolysis (#35)

Candice Menezes 1 2 , Ahmed Haliem 1 2 , Mark Parsons 3 , Andrew Bivard 4 5 , Dominic Italiano 3 , Leonid Churilov 2 6 7 , Geoffrey Donnan 2 3 , Stephen Davis 2 3 , Bruce Campbell 2 3 , Henry Zhao 2 3
  1. Faculty of Medicine, Dentistry & Health Sciences, University of Melbourne, Melbourne, Victoria, Australia
  2. Neurology, Royal Melbourne Hospital, Melbourne, Victoria, Australia
  3. Medicine, Royal Melbourne Hospital, Melbourne, Victoria, Australia
  4. Melbourne Brain Centre, Royal Melbourne Hospital, Melbourne, Victoria, Australia
  5. Sydney Brain Centre, University of New South Wales, Sydney, NSW, Australia
  6. Medicine, University of Melbourne, Melbourne, Victoria, Australia
  7. Medicine, Austin Health, Melbourne, Victoria, Australia

Introduction:

Post-thrombolysis, there is no routine intermediate imaging performed that allows assessment of when reperfusion occurs. Many patients receiving pre-hospital thrombolysis on the Melbourne Mobile Stroke Unit(MSU) undergo an in-hospital admission CT-perfusion (CTP) which presents a unique opportunity to understand the impact of early post-thrombolysis reperfusion. 

Aims

We aimed to determine the proportion of patients receiving pre-hospital thrombolysis who present with early reperfusion changes on hospital admission CTP. Additionally, we assessed the association of early reperfusion to 90-day outcomes.  

 

Methods 

We included patients receiving pre-hospital thrombolysis (without concurrent thrombectomy) on the Melbourne MSU with hospital admission CTP from three comprehensive centres. Early reperfusion was defined as a visually determined area of milder hypoperfusion (below TMax >6sec) consistent with presenting symptoms. These were subsequently grouped as full (mild hypoperfusion of entire CTP lesion) or partial(mild hypoperfusion of at least part of the CTP lesion). We then correlated these to follow-up imaging (≥24h) to determine if the final infarct was smaller than that predicted by admission CTP and 90-day modified Rankin Scale (mRS) outcomes.



Results

We included a total of 51 patients with median NIHSS of 7 (IQR 5-10.3) and onset-to-CT of 59.5min (IQR 46.3-100.5). Of these, 8 (15.7%) showed full and 16 (31.3%) showed partial early reperfusion, whilst 27(52.9%) showed no significant early reperfusion. Time metrics, baseline severity and tenecteplase use did not significantly differ between these groups. Any early reperfusion was associated with a higher proportion of reduced final infarct in comparison to patients that did not achieve early reperfusion (71.9% vs 52.6%), and improved 90-day outcomes(mRS 0/1/baseline 59.4% vs 42.1%) were statistically non-significant (p>0.05).  



Conclusion

Almost 50% of patients showed evidence of early reperfusion following fast pre-hospital thrombolysis on the MSU and these were associated with trends towards smaller final infarct size and better 90-day outcomes. We require confirmation of these results with a larger study.