Endovascular thrombectomy after large-vessel ischemic

stroke: a meta-analysis of individual patient data fromfive randomised trials

HERMES CollaboratorsHighly Effective Reperfusion evaluated in Multiple Endovascular Stroke trials (HERMES)

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Disclosure slide

• Medtronic provided an unrestricted grant to the University of Calgary for the HERMES collaboration

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HERMES collaboration

• 5 trials published in early 2015

• All supported endovascular thrombectomy as a definitive treatment for anterior circulation, large vessel occlusive ischemic stroke

• Pooled analyses of individual patient data will allow:

– Greater precision

– Analysis of subgroups

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Methods

• A statistical analysis plan was formulated and finalized prior to data pooling

• Two statisticians collated and pooled the data – both are independent of the investigators and the relevant sponsors

• A steering committee oversaw the analysis

• All interpretation and analyses were independent of the study sponsors

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Methods

• A literature review confirmed that 5 major trials examining modern endovascular stroke treatment were published at the time of analysis

• A mixed effects model, with study as a random variable was used to assess the treatment effect across the 5 studies

• Sub-groups of interest were age, sex, occlusion location, ASPECTS score, treatment with alteplase and time from randomization

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Baseline Characteristics(N=1287)

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Baseline Characteristics

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Overall Treatment EffectNNT = 2.6

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Overall Treatment Effect

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Treatment effect is the same in men and women (pint=0.36)

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Treatment effect by agemRS 0-2 at 90 days

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Treatment effect is strong across occlusion sites (pint=0.35)

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Effect size by NIHSS, time to randomization, and tPA use

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Treatment effect is present for all ASPECTS category (pint=0.49)

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NOTE:42% = 5;30% = 4;28% < 4

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Constant Effect Size by Age

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Constant effect size by NIHSS

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Conclusions

• Endovascular treatment is a highly effective therapy across all subgroups

• These data may provide additional support for endovascular treatment in subgroups not addressed in individual trials

• Caution is still warranted in interpreting results for groups with small numbers

• The full paper and supplementary data are published on-line today in the Lancet

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Highly Effective Reperfusion evaluated in Multiple Endovascular Stroke trials

(HERMES) collaboration

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Thank You!