Abstract WMP11: The Association between Endovascular Reperfusion and Favorable Clinical Response Is Similar in Older and Younger Stroke Patients

Abstract

Background: Older stroke patients generally have poorer clinical outcomes than younger stroke patients. We aimed to determine if the clinical response following endovascular reperfusion differs between older and younger patients with the Target Mismatch profile. Methods: Stroke patients enrolled in the DEFUSE 2 study underwent MRI diffusion (DWI) and perfusion (PWI) weighted imaging prior to endovascular treatment. Target Mismatch was defined as a ratio of PWI (Tmax >6s) over DWI volume >1.8, DWI volume <70ml, and a PWI (Tmax >10s) volume <100ml. Favorable clinical response was defined as a >8 point improvement on the NIHSS or an NIHSS score of 0-1 at 30 days. The relationship between baseline clinical and neuroimaging variables and favorable clinical response, was assessed using logistic regression. In addition, we evaluated the interaction of age and reperfusion on favorable clinical response and compared the effect of reperfusion between younger (age ≤ 80 years) and older (age > 80 years) patients. Results: Seventy-eight patients had a Target Mismatch and forty-two patients had a favorable clinical response. Age (p<0.01), reperfusion status (p<0.01), baseline DWI volume (p=0.07), hypertension (p<0.01) and history of stroke or TIA (p<0.01) were associated with favorable clinical response in univariate analyses. In multivariate analysis, age (p<0.05), reperfusion (p<0.01) and baseline DWI volume (p<0.05) were independent predictors of favorable clinical response. The age by reperfusion status interaction was not significant in the multivariate model (p = 0.3). Additionally, there was no significant difference between the odds ratio for favorable clinical response with reperfusion in patients ≤80 years (n = 58; OR = 6.2, 95% CI = 1.7 - 24.4) and those above 80 years (n = 20; OR = 2.1, 95% CI = 0.2 - 21.1) (p = 0.3 for the difference between the odds ratios). Conclusion: Target Mismatch patients who are younger have overall better clinical outcomes than older patients with the Target Mismatch. The association between endovascular reperfusion and favorable clinical response did, however, not differ between younger and older stroke patients. These results argue against the use of an age cutoff for endovascular stroke therapy.