ISCHEMIC STROKE / THERAPY
Acute stroke in an anticoagulated patient
Created 18/04/2022, last revision 06/11/2023
- 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?
- the patient is otherwise suitable for recanalization therapy
- 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 anticoagulation – timing 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? |