Endovascular Therapy in Mild Ischemic Strokes Presenting Under 6 hours: An International Survey

https://doi.org/10.1016/j.jstrokecerebrovasdis.2020.105234Get rights and content

Abstract

Background

Endovascular therapy (EVT) for patients with mild ischemic stroke (NIHSS ≤5) and visible intracranial occlusion remains controversial, including within 6 hours of symptom onset. We conducted a survey to evaluate global practice patterns of EVT in this population.

Methods

Vascular stroke clinicians and neurointerventionalists were invited to participate through professional stroke listservs. The survey consisted of six clinical vignettes of mild stroke patients with intracranial occlusion. Cases varied by NIHSS, neurological symptoms and occlusion site. All had the same risk factors, time from symptom onset (5h) and unremarkable head CT. Advanced imaging data was available upon request. We explored independent case and responder specific factors associated with advanced imaging request and EVT decision.

Results

A total of 482/492 responders had analyzable data ([median age 44 (IQR 11.25)], 22.7% women, 77% attending, 22% interventionalist). Participants were from USA (45%), Europe (32%), Australia (12%), Canada (6%), and Latin America (5%). EVT was offered in 48% (84% M1, 29% M2 and 19% A2) and decision was made without advanced imaging in 66% of cases. In multivariable analysis, proximal occlusion (M1 vs. M2 or A2, p<0.001), higher NIHSS (p<0.001) and fellow level training (vs. attending; p=0.001) were positive predictors of EVT. Distal occlusions (M2 and A2) and higher age of responders were independently associated with increased advanced imaging requests. Compared to US and Australian responders, Canadians were less likely to offer EVT, while those in Europe and Latin America were more likely (p<0.05).

Conclusions

Treatment patterns of EVT in mild stroke vary globally. Our data suggest wide equipoise exists in current treatment of this important subset of mild stroke.

Introduction

Endovascular therapy (EVT) has revolutionized treatment of patients with moderate to severe ischemic stroke and concurrent occlusion, but patients with mild ischemic stroke (National Institutes of Health Stroke Scale [NIHSS] ≤5) were either excluded,1, 2, 3, 4–5 or markedly underrepresented in large randomized controlled trials.6, 7–8 The role of EVT in patients with mild symptoms and a visible intracranial occlusion (in the large or medium vessels) is unknown.

About 14% of patients with mild ischemic stroke present with visible intracranial occlusion, and despite seemingly benign initial presentations, up to one third of these patients suffer significant disability and death within 90 day follow up.9, 10–11 The safety of EVT in mild stroke is largely unknown though several retrospective studies have reported the use of EVT in mild stroke worldwide.12–14 Despite these analyses suggesting possible benefit of EVT in mild stroke, there are no randomized clinical trials to support these observations. Correspondingly, the American Heart Association/American Stroke Association gives a Class II, Level of Evidence B recommendation for EVT in patients with a NIHSS <6, presenting within 6 hours of symptom onset or last known well, and a causative occlusion of the internal carotid artery (ICA), proximal MCA (M1), or M2/M3 segment.15

In routine clinical practice, physicians need to make complex decisions regarding patient selection for advanced imaging and reperfusion in those presenting with mild neurological symptoms and concurrent vessel occlusion. The lack of data from clinical trials in this population translate into uncertainties regarding appropriate acute therapies and wide practice variability amongst physicians. Furthermore, evidence is limited regarding which non-clinical factors influence physician decision to pursue advanced imaging and/or endovascular therapy in patients with mild stroke.

The present survey aims to study global variations in clinical practice regarding immediate decisions for obtaining advanced imaging and offering EVT to patients with mild stroke and concurrent vessel occlusion.

Section snippets

Methods

All data from this study is available from the corresponding author upon request.

Results

Between April 4, 2019 and June 30, 2019, the survey link was sent to various professional listservs with estimated distribution list of over 4,000 across the globe. Among these, 492 opened the survey link and 482 had analyzable data, consisting of at least one out of the six cases. A total of 2406 responses were available for analysis. A summary of clinical case scenarios and treatment decisions can be found in Table 1.

The mean age of responders was 45.1 (± 9.1) years and 22.7% were women. The

Discussion

This international survey evaluated current practice patterns of offering endovascular therapy to patients with mild ischemic symptoms and relevant intracranial occlusion. Attending physicians and older practitioners were more likely to request advanced imaging prior to making a final decision, and younger age and fellow responders were more likely to offer EVT. Geographic location of practice also significantly affected therapeutic decisions. As compared to responders in Australia and USA,

Conclusions

In summary, this study highlights global variability in use of advanced imaging and pursuit of endovascular therapy for mild stroke patients with intracranial occlusion. Further research is crucial to improve the evidence base for this important subset of stroke patients and to inform clinical guidelines.

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgments

Study data were collected and managed using REDCap electronic data capture tools hosted at University of Miami.

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    These authors contributed equally to this work.

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