Local Versus Systemic Thrombolysis for Acute Ischemic Stroke (SYNTHESIS)

Completed

Phase 3 Results

Trial Description

The purpose of this study is to determine whether intra-arterial rt-PA within 6 hours from an ischemic stroke onset, compared with intravenous infusion of the same drug within 3 hours, increases the proportion of independent survivors at 3 months.

Detailed Description

"Stroke is a major cause of death and severe disability.The only effective, available therapy, within few hours of stroke onset, is rt-PA, a thrombolytic agent. Preliminary experience but not from properly conducted randomized trials indicates that intra-arterial treatment might be more effective than intravenous therapy for some vascular lesions. Intravenous application has not been tested directly against intra-arterial treatment and we do not known the relative clinical effectiveness with these two routes of administration. Eligible patients will be randomized to receive either IV rt-PA (0.9mg/kg; max 90 mg), 10% of which would be infused over 1 minute, and the remainder over 60 min, or IA rt-PA within the thrombus by means of microcatheter. In patients allocated to IA rt-PA the angiogram is performed as soon as possible within 6 hours of stroke onset; IV heparin has to be initiated (2000 U bolus followed by 500 U7hr infusion) and rt-PA is delivered at a rate of about 90 mg/hr for maximum one hour at the dose needed for recanalization up to 0.9 mg/Kg (max 90 mg). Antithrombotics and anticoagulants are disallowed during the first 24 hours (except heparin used during the angiogram). After 24 hrs, all patients will be considered for long-term antiplatelet or anticoagulant therapy. Follow-up will take place at 7 days, discharge, or transfer, whichever is first; and again at 3 months. 4 centers are currently authorized for the start-up phase; 15 centers in Italy have applied for an expansion phase of the study (SYNTHESIS EXPANSION), with financial support from Italian National Agency for Drugs (AIFA).The two phases of the study will be analysed separately and will be considered in a pooled analysis.

Conditions

Interventions

  • IV rt-PA Drug
    Other Names: Alteplase, Activase
    Intervention Desc: Thrombolytic
  • IA rt-PA Drug
    Intervention Desc: Intra-Arterial
  • Cal intraarterial recombinant tissue plasminogen activator Drug
    ARM 1: Kind: Experimental
    Label: 1
    Description: local intraarterial recombinant tissue plasminogen activator
  • Intravenous (IV) rt-PA Drug
    Intervention Desc: IV thrombolytic treatment is started immediately after randomization, within 4.5 h of symptoms onset. IV rt-PA is administered at a dose of 0.9 mg/kg (max 90 mg), 10% of which is given as a bolus, followed by the delivery of the remaining 90% as a constant infusion over 60 mins
    ARM 1: Kind: Experimental
    Label: 2
    Description: intravenous (IV) rt-PA
  • Local intraarterial recombinant tissue plasminogen activator Drug
    Intervention Desc: Endovascular treatment must be performed asap after random.and definitely within 6h from symp. onset.It includes intrarterial thrombolysis with rt-PA,if necessary,associated to or substituted by mechanical clot disruption and/or retrieval.Fibrinolytic therapy should be performed within 1h,the full dose of rt-PA infusion should not exceed 0.9 mg/kg (max 90 mg in the case of body weight ≥100 kg).If a complete recanalization is achieved,rt-PA infusion can be interrupted before reaching the maximum dosage.The option of performing a thrombolysis by mechanical means to obtain a mechanical disintegration/shift/detach/fissure of the thrombus and/or a retraction/aspiration can be considered on the basis of the type,location and characteristics of the occlusion.These choices may involve the use of the microguidewire as a mechanical instrument to favour the disintegration of the thrombus,using systems to capture the thrombus by extraction or more complex systems to crush and aspirate the thrombus
    ARM 1: Kind: Experimental
    Label: 1
    Description: local intraarterial recombinant tissue plasminogen activator
  • Local interarterial recombinant tissue plasminogen activator Drug
    Intervention Desc: Endovascular treatment must be performed asap after random.and definitely within 6h from symp. onset.It includes intrarterial thrombolysis with rt-PA,if necessary,associated to or substituted by mechanical clot disruption and/or retrieval.Fibrinolytic therapy should be performed within 1h,the full dose of rt-PA infusion should not exceed 0.9 mg/kg (max 90 mg in the case of body weight ≥100 kg).If a complete recanalization is achieved,rt-PA infusion can be interrupted before reaching the maximum dosage.The option of performing a thrombolysis by mechanical means to obtain a mechanical disintegration/shift/detach/fissure of the thrombus and/or a retraction/aspiration can be considered on the basis of the type,location and characteristics of the occlusion.These choices may involve the use of the microguidewire as a mechanical instrument to favour the disintegration of the thrombus,using systems to capture the thrombus by extraction or more complex systems to crush and aspirate the thrombus
    ARM 1: Kind: Experimental
    Label: 1
    Description: local intraarterial recombinant tissue plasminogen activator

Trial Design

  • Allocation: Randomized
  • Masking: Open Label
  • Purpose: Treatment
  • Endpoint: Safety/Efficacy Study
  • Intervention: Parallel Assignment

Patient Involvement

Eligible patients will be randomized to receive either IV rt-PA (0.9mg/kg; max 90 mg), 10% of which would be infused over 1 minute, and the remainder over 60 min, or IA rt-PA within the thrombus by means of microcatheter. In patients allocated to IA rt-PA the angiogram is performed as soon as possible within 6 hours of stroke onset; IV heparin is to be initiated (2000 U bolus followed by 500 U7hr infusion) and rt-PA is delivered at a rate of about 90 mg/hr for maximum one hour at the dose needed for recanalization up to 0.9 mg/Kg (max 90 mg). Antithrombotics and anticoagulants are disallowed during the first 24 hours (except heparin used during the angiogram). After 24 hrs, all patients will be considered for long-term antiplatelet or anticoagulant therapy. Follow-up will take place at 7 days, discharge, or transfer, whichever is first; and again at 3 months.

Outcomes

Type Measure Time Frame Safety Issue
Primary Independence based on Modified Ranken Scale score and mortality at 3 months.
Secondary NIHSS score of 6 or less at day 7; proportion of symptomatic intracranial hemorrhages and recurent ischemic stroke.
Primary To assess whether local intra-arterial (LIA) recombinant tissue plasminogen activator rt-PA, as compared to intravenous (IV) rt-PA, increases survival free of disability (modified Rankin score of 0 or 1) . 3 months No

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