Dual Antiplatelet Therapy After Cerebrovascular Accident (CVA)
Dual antiplatelet therapy (DAPT) is recommended for a short duration of 21-30 days following a minor ischemic stroke or high-risk TIA, but not for long-term secondary prevention after a CVA. 1
Acute Management of Ischemic Stroke/TIA
Very High-Risk TIA or Minor Stroke (NIHSS 0-3)
- For patients with very high-risk TIA (ABCD2 score >4) or minor stroke of noncardioembolic origin, a combination of clopidogrel and aspirin should be given for a duration of 21-30 days 1
- Initial loading doses should include:
- Clopidogrel: 300-600 mg loading dose
- Aspirin: 160 mg loading dose 1
- DAPT should be started as soon as possible after brain imaging, within 24 hours of symptom onset, and ideally within 12 hours 1
- After the 21-30 day DAPT period, patients should resume antiplatelet monotherapy indefinitely 1
Timing Considerations
- DAPT initiated within 72 hours after stroke onset leads to a lower risk of new stroke at 90 days than aspirin therapy alone (7.3% vs 9.2%), but is associated with a higher risk of moderate-to-severe bleeding (0.9% vs 0.4%) 2
- The most benefit is seen when DAPT is started early - within 24 hours of symptom onset 1
Long-Term Secondary Prevention
- For long-term secondary prevention after the initial 21-30 day period, single antiplatelet therapy with either aspirin or clopidogrel is recommended 1
- In patients with non-cardioembolic cerebral ischemic events, anticoagulation is not recommended (Class III, Level B) 1
- The combination of aspirin and dipyridamole is another option for long-term monotherapy after the initial DAPT period 3
Special Considerations
Carotid Revascularization
- Following carotid artery stenting (CAS), DAPT is typically continued for 4-6 weeks if a single-layer stent is used (and up to 3 months with 'mesh' stents), after which single antiplatelet therapy is advised 1
- For patients undergoing carotid endarterectomy (CEA), clopidogrel or low-dose aspirin is usually administered on day 1 post-CEA and continued for 1-3 months 1
- Before and for a minimum of 30 days after CAS, DAPT with aspirin (81-325 mg daily) plus clopidogrel (75 mg daily) is recommended (Class I, Level C) 1
Bleeding Risk
- The risk of major hemorrhage is significantly increased with DAPT compared to monotherapy (0.9% vs 0.4%) 1
- Intracranial hemorrhage, though uncommon (0.2%-0.3% annually), is the most serious complication of DAPT 4
- Patients with a history of stroke or TIA harbor a particularly high risk for intracranial hemorrhage when treated with DAPT 4
- For patients on DAPT, GI protection may be considered in patients at higher risk of GI bleeding 1
Algorithm for DAPT Use After CVA
Acute phase (first 24-72 hours after CVA):
Short-term phase (21-30 days):
- Continue DAPT with clopidogrel 75 mg daily plus aspirin 100 mg daily 1
- Monitor for bleeding complications
Long-term phase (beyond 30 days):
Caveats and Pitfalls
- DAPT should not be continued beyond the recommended 21-30 day period due to increased bleeding risk without additional benefit 1
- In patients treated with tissue plasminogen activator (alteplase), initiation of antiplatelet agents should be delayed until after the 24-hour post-thrombolysis scan has excluded intracranial hemorrhage 1
- For patients with very high-risk TIA or minor stroke caused by high-grade carotid stenosis who are candidates for urgent carotid intervention, consultation with the interventionalist or surgeon is needed to determine appropriate timing and selection of antiplatelet therapy 1
- In dysphagic patients, ASA (80 mg daily) and clopidogrel (75 mg daily) may be given by enteral tube or ASA by rectal suppository (325 mg daily) 1