Acute stroke in an anticoagulated patient

David Goldemund M.D.
Updated on 06/11/2023, published on 18/04/2022

  • anticoagulants have become the mainstay of stroke prevention in patients with atrial fibrillation (AFib) or other potential sources of cardioembolism
  • however, despite anticoagulant therapy, ischemic stroke can occur, and we then face two basic scenarios:
    • the patient is otherwise suitable for recanalization therapy
      • can the anticoagulant´s drug effect be neutralized to allow intravenous thrombolysis (IVT)?
      • prefer direct mechanical thrombectomy (dMT) over bridging therapy?
    • the patient is not not suitable for recanalization therapy
      • continue with anticoagulation therapy?
      • halt the treatment for 7-14 days and then restart?
      • when oral anticoagulation is discontinued, should aspirin (ASA) or low molecular weight heparin (LMWH) be administered temporarily? If so, at what dose?
  • before resuming the anticoagulant therapy, analyze the reasons for its earlier failure
    • poorly adjusted warfarin with low INR
    • underdosing, other drug interactions, 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
  • continuing 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%); the potential benefit of early anticoagulation is negated by an increased incidence of bleeding
    • in the IST trial (comparing UFH vs. placebo), the recurrence risk in the heparin arm was approx. 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 compared LMWH with 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 simple withdrawal; however, research on this is limited
  • 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 bleeding
    • a meta-analysis of 3 trials (IST, CAST, and HAEST) showed minimal benefit with ASA and no benefit with heparin
  • LMWH bridging
    • therapeutic doses should not be administered
    • used only as mini-heparinization for VTE prophylaxis; intermittent pneumatic compression (IPC) is preferred for moderate-to-severe stroke  → VTE prevention
  • the decision to discontinue or resume anticoagulation is highly individualized
  • when restarting the therapy, either the current DOAC or another drug can be chosen – the RENO-EXTENT trial showed similar recurrence rates for both strategies
effective anticoagulation ineffective anticoagulation
TIA warfarin – increase target INR or switch to DOAC (if possible)
DOAC – verify correct dosage and laboratory efficacy or switch to another agent
start DOAC (if possible)
otherwise, titrate warfarin when bridging LMWH
minor stroke discontinue anticoagulation + consider ASA bridging 100-300 mg
OR  continue with anticoagulation
( based on NIHSS and extent of ischemia – ideally according to DWI finding)
consider ASA bridging 100-300 mg
delayed anticoagulationtiming of anticoagulant therapy
moderate-severe stroke
discontinue anticoagulation
consider ASA bridging 100-300 mg
delayed anticoagulation – timing of anticoagulant therapy
consider ASA bridging 100-300 mg
delayed anticoagulation – timing of anticoagulant therapy
Seek another etiology. Is there an indication for concurrent antiplatelet therapy?

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Acute stroke in anticoagulated patient