Dr Eva MistryEva Mistry, MD
Results from a retrospective, single-center comparative analysis show that patients with and without prestroke disability demonstrate similar rates of successful clinical and procedural outcomes after endovascular therapy.1

The analysis looked at patients trichotomized based on prestroke modified Rankin Scale (mRS) 0 or 1: no significant (mRS 0 to 1), moderate (mRS 2 to 3), and significant disability (mRS 4 to 5). Investigators compared the proportion of patients that had a successful 90-day outcome, while secondary outcome measures included successful recanalization, symptomatic hemorrhage, and in-hospital death.

Successful outcome was reported in 42% (58/137) of patients with no significant disability, 46% (46/100) of those with moderate disability, and 60% (6/10) of those with significant disability. There were no differences noted in the rates of symptomatic hemorrhage or successful recanalization. Investigators reported that the proportion with in-hospital death increased with prestroke disability, 6.7%, 14.9%, 33.3%, respectively (P = .02).1

Eva Mistry, MD, of the department of neurology, Vanderbilt University Medical Center, spoke with NeurologyLive in an interview about the results from the outcome analysis that was presented at the 2019 American Academy of Neurology (AAN) Annual Meeting in Philadelphia, Pennsylvania.

NeurologyLive: What were the main findings of this study?

Eva Mistry, MD: The main findings of this study are that patients with prestroke disability, defined as prestroke modified Rankin Score (mRS) of 2–3, had a similar odds of having good outcome, defined as no increase in 90-day mRS (i.e. no accumulation of additional disability), when compared to those without prestroke disability (mRS 0-1). 

How do these patients differ from those with prestroke disability, in terms of how they need to be treated?

In our study, patients with prestroke disability were older and more likely to be females. A higher proportion of patients with prestroke disability had concurrent comorbidities such as hypertension and tobacco use. Interestingly, they also presented with a higher NIH stroke scale score. Thus far, there is no good data on how these patients should be treated, as far as endovascular stroke treatment is concerned. This is mainly because randomized clinical trials evaluating the efficacy of endovascular therapy have largely excluded patients with baseline disability. When approaching patients with acute stroke due to a large vessel occlusion, clinicians often times refer to the clinical guidelines. These guidelines are reliant upon the previously mentioned trials and recommend only offering endovascular treatment to patients with no prestroke disability. Thus, anecdotally in our experience, patients with prestroke disability are excluded from endovascular treatment for acute stroke.   

What are the clinical implications of this analysis?

Our results should be interpreted with an important limitation that we are underpowered to make a definitive claim for non-inferiority of endovascular treatment in patients with prestroke disability. 

Were any of the data surprising or unexpected in any way?

We did not find this finding surprising. In fact, they uphold our initial hypothesis that patients with prestroke disability have similar likelihood of retaining their baseline functional status compared to those without any baseline disability. We also found that procedural success, defined as achievement of successful recanalization, was similar between these groups. We also showed that the rate of most feared complication of acute stroke treatment, symptomatic intracerebral hemorrhage, was similar between the 2 groups.

What still needs to be done to confirm this approach?

Prospective multicenter studies are needed to confirm our findings. These studies may uncover institutional differences in outcomes of endovascularly-treated patients with prestroke disability. Further, evaluation of barriers in terms of clinician behavior for implementation of endovascular treatment in these patients should be undertaken.

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1. Salwi S, Mistry A, Espaillat K, et al. Comparative Outcome Analysis of Endovascular Acute Ischemic Stroke Treatment in Patients With and Without Pre-stroke Disability. Presented at: 2019 American Academy of Neurology Annual Meeting. May 4-10, 2019; Philadelphia, PA. Abstract: S57.009.