ISCHEMIC STROKE / THERAPY

Created 18/04/2022, last revision 13/02/2023

• anticoagulants have become the mainstay of stroke prevention in patients with atrial fibrillation or other potential sources of cardioembolism
• however, even with this therapy (including DOACs), ischemic stroke can occur, and we then address 2 basic scenarios in the acute phase:
  • the patient is a candidate for recanalization therapy
    • can the effect of an anticoagulant drug be neutralized and IVT administered?
    • prefer direct thrombectomy over bridging therapy?
  • the patient is not a candidate for recanalization therapy
    • continue anticoagulation therapy?
    • discontinue therapy for 7-14 days and then restart?
    • when discontinuing oral anticoagulation, should we start ASA or LMWH temporarily, and at what dose?
• before restarting the anticoagulant therapy, analyze its previous failure
  • poorly adjusted warfarin with low INR?
  • underdosing or discontinuation of DOACs?
  • other stroke mechanisms? (dissection, vasculitis, etc.)

The patient is a candidate for recanalization therapy

The patient is NOT a candidate for recanalization therapy

• initiation of anticoagulation therapy in the early stages of stroke is generally not recommended
• continuation of effective anticoagulation therapy reduces the risk of recurrence but also increases the risk of hemorrhagic transformation of ischemia (HTI)
• the risk of recurrence of cardioembolic stroke in the first 14 days is relatively low according to studies (about 5-8%), and the potential benefit of early anticoagulation is negated by a higher incidence of hemorrhage
  • in the IST trial (UFH vs. placebo), the risk of recurrence in the heparin arm was about 2.3 vs. 4.9%/14 days, but the incidence of ICH was higher (2.8 vs. 0.4%) ⇒ no net benefit
  • the HAEST trial tested LMWH vs. aspirin – the difference in stroke recurrence rate was non-significant (approx. 8% in 14 days in both groups)
• rapid neutralization of the anticoagulant effect may reduce the risk of HTI compared with gradual withdrawal; however, studies are lacking
• ASA bridging
  • according to the IST and CAST trials, the absolute reduction in stroke recurrence is approx. 1% (similar to patients without AFib). ASA does not appear to significantly reduce the risk of cardioembolism nor increase the risk of hemorrhage
  • a meta-analysis of 3 trials (IST, CAST, and HAEST) showed little benefit with ASA and no benefit with heparin
• LMWH bridging
  • not at therapeutic doses
  • used only as mini-heparinisation in VTE prophylaxis; prefer IPC for moderate-to-severe strokes  → VTE prevention
• the decision to discontinue or restart anticoagulation is highly individual
• when restarting therapy, the current DOAC or another drug can be used – the RENO-EXTENT trial showed similar recurrence rates for both strategies