03910nas a2200541   4500000000100000008004100001653001100042653001100053653000900064653000900073653002200082653002400104653002400128653001100152653003300163653001900196653002200215653004200237653003200279653002100311653003500332653003200367653002400399653002500423653003300448653003100481100001900512700001600531700002400547700001500571700002100586700001700607700001800624700001900642700001700661700001600678700001500694700001600709700002000725700002100745700001900766700003000785245014500815300001200960490000700972520237500979022001403354       2017                            d10aFemale10aHumans10aAged10aMale10aTreatment Outcome10aSingle-Blind Method10aProspective Studies10aStroke10aMulticenter Studies as Topic10aBrain Ischemia10aAged, 80 and over10aRandomized Controlled Trials as Topic10aAdministration, Intravenous10aInternationality10aMagnetic Resonance Angiography10aArterial Occlusive Diseases10aFibrinolytic Agents10aThrombolytic Therapy10aTissue Plasminogen Activator10aTomography, X-Ray Computed1 aDemchuk Andrew1 aYan Bernard1 avon Kummer Rüdiger1 aMair Grant1 aAdami Alessandro1 aWhite Philip1 aAdams Matthew1 aFarrall Andrew1 aSellar Robin1 aSakka Eleni1 aPalmer Jeb1 aPerry David1 aLindley Richard1 aSandercock Peter1 aWardlaw Joanna1 aIST-3 Collaborative Group00aArterial Obstruction on Computed Tomographic or Magnetic Resonance Angiography and Response to Intravenous Thrombolytics in Ischemic Stroke.  a353-3600 v483 a<p>
<b>BACKGROUND AND PURPOSE: </b>Computed tomographic angiography and magnetic resonance angiography are used increasingly to assess arterial patency in patients with ischemic stroke. We determined which baseline angiography features predict response to intravenous thrombolytics in ischemic stroke using randomized controlled trial data.
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<b>METHODS: </b>We analyzed angiograms from the IST-3 (Third International Stroke Trial), an international, multicenter, prospective, randomized controlled trial of intravenous alteplase. Readers, masked to clinical, treatment, and outcome data, assessed prerandomization computed tomographic angiography and magnetic resonance angiography for presence, extent, location, and completeness of obstruction and collaterals. We compared angiography findings to 6-month functional outcome (Oxford Handicap Scale) and tested for interactions with alteplase, using ordinal regression in adjusted analyses. We also meta-analyzed all available angiography data from other randomized controlled trials of intravenous thrombolytics.
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<b>RESULTS: </b>In IST-3, 300 patients had prerandomization angiography (computed tomographic angiography=271 and magnetic resonance angiography=29). On multivariable analysis, more extensive angiographic obstruction and poor collaterals independently predicted poor outcome (P&lt;0.01). We identified no significant interaction between angiography findings and alteplase effect on Oxford Handicap Scale (P≥0.075) in IST-3. In meta-analysis (5 trials of alteplase or desmoteplase, including IST-3, n=591), there was a significantly increased benefit of thrombolytics on outcome (odds ratio&gt;1 indicates benefit) in patients with (odds ratio, 2.07; 95% confidence interval, 1.18-3.64; P=0.011) versus without (odds ratio, 0.88; 95% confidence interval, 0.58-1.35; P=0.566) arterial obstruction (P for interaction 0.017).
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<b>CONCLUSIONS: </b>Intravenous thrombolytics provide benefit to stroke patients with computed tomographic angiography or magnetic resonance angiography evidence of arterial obstruction, but the sample was underpowered to demonstrate significant treatment benefit or harm among patients with apparently patent arteries.
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<b>CLINICAL TRIAL REGISTRATION: </b>URL: http://www.isrctn.com. Unique identifier: ISRCTN25765518.
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  a1524-4628