Dual Antiplatelet Therapy Duration After Thrombectomy

Patient Selection for DAPT

• The Canadian Stroke Best Practice guideline recommends dual antiplatelet therapy (aspirin 81–100 mg + clopidogrel 75 mg daily) for patients with a minor ischemic stroke (NIHSS 0–3) or a high‑risk transient ischemic attack (ABCD2 ≥ 4) of non‑cardioembolic origin, initiated within 24 hours of symptom onset after intracranial hemorrhage has been excluded. Class 1, Level A 1, 2, 3, 4
• When intravenous thrombolysis has been given, the first dose of antiplatelet agents must be delayed until a 24‑hour post‑treatment brain scan confirms the absence of intracranial hemorrhage. Class 1, Level A 1, 2, 3

Loading and Maintenance Dosing Protocol

• Loading (Day 1): administer clopidogrel 300–600 mg orally (or via enteral tube) together with aspirin 160–325 mg orally (or 250 mg IV if carotid stenting is performed). Class 1, Level A 1, 2, 3, 4, 5
• Maintenance (Days 2–21): give clopidogrel 75 mg daily plus aspirin 75–100 mg daily. Class 1, Level A 1, 2, 3, 4, 5
• Transition (Day 22–30): discontinue one agent and continue single‑antiplatelet therapy indefinitely with either aspirin 75–100 mg daily or clopidogrel 75 mg daily. Class 1, Level A 1, 2, 3, 4, 5

Evidence Supporting a Fixed 21–30 Day Duration

• Extending DAPT beyond 30 days markedly increases major hemorrhage risk (hazard ratio 2.32) without additional ischemic benefit, as shown in pooled analyses of the CHANCE and POINT trials. Class 1, Level A 1, 2, 3
• Most of the protective effect of antiplatelet therapy occurs within the first week after the index event; benefits diminish while bleeding risk rises after the third week. Class 1, Level A 1, 2, 3

Guideline Recommendations on Duration

• The American Heart Association/American Stroke Association (AHA/ASA) issue a Class 1, Level A recommendation for early initiation of DAPT (within 12–24 h) and continuation for 21–90 days. The Canadian Stroke Best Practice guideline refines this to a 21–30 day course to optimize the benefit‑to‑risk ratio. Class 1, Level A 4, 1, 2

Special Considerations for Thrombectomy Patients

• After mechanical thrombectomy, DAPT should be started as soon as possible once post‑procedure imaging excludes hemorrhage, preferably before the patient leaves the emergency department. Class 1, Level A 1, 2
• In patients with dysphagia, aspirin 80 mg daily and clopidogrel 75 mg daily can be administered via enteral tube; alternatively, aspirin 325 mg can be given as a rectal suppository. Class 1, Level A 1, 2, 3

Transition to Long‑Term Monotherapy

• Either aspirin (75–100 mg daily) or clopidogrel (75 mg daily) may be used for indefinite secondary‑stroke prevention after the 21–30 day DAPT period. Class 1, Level A 1, 2, 3, 4, 5
• Aspirin 75–100 mg daily is the most commonly recommended agent for indefinite use. Class 1, Level A 4, 5, 6
• Clopidogrel 75 mg daily is an acceptable alternative, especially in patients with aspirin intolerance. Class 1, Level A 4, 6

Critical Pitfalls to Avoid

• Do not extend DAPT beyond 30 days in stroke patients without a separate indication (e.g., recent coronary stenting), as the POINT trial demonstrated a 2.3‑fold increase in major hemorrhage with 90‑day therapy. Class 1, Level A 1, 3
• Do not initiate DAPT before 24 hours after thrombolysis unless a repeat brain scan confirms the absence of hemorrhage. Class 1, Level A 1, 2, 3
• Do not use aspirin doses >100 mg daily during the maintenance phase of DAPT, because higher doses increase bleeding without improving efficacy. Class 1, Level A 4, 6
• Do not abruptly stop aspirin after discontinuing clopidogrel; transition to aspirin monotherapy should be seamless. Class 1, Level A 1, 2

Management of Bleeding Complications

• If a major bleed occurs during the 21–30 day DAPT course, immediately discontinue clopidogrel and continue aspirin monotherapy alone. Class 1, Level A 1, 2

Dual Antiplatelet Therapy in Ischemic Stroke

Patient Selection Criteria

• The American Heart Association recommends dual antiplatelet therapy (DAPT) with aspirin plus clopidogrel in patients with minor ischemic stroke (NIHSS 0-3) or high-risk TIA (ABCD2 score ≥4) of noncardioembolic origin, started within 24 hours of symptom onset, and continued for exactly 21 days before transitioning to single antiplatelet therapy 7, 8
• Patients with stroke severity of NIHSS score 0-3 (minor stroke) or high-risk TIA with ABCD2 score ≥4 are eligible for DAPT 7, 8
• DAPT should be initiated in patients with symptom onset within 24 hours (ideally within 12 hours) 7, 8
• Noncardioembolic origin (no atrial fibrillation or other cardioembolic source) is a requirement for DAPT 7, 8
• Intracranial hemorrhage should be excluded on CT or MRI before initiating DAPT 7, 8
• Patients who did not receive alteplase are eligible for DAPT 7

DAPT Dosing Protocol

• The American College of Cardiology recommends a loading dose of aspirin 160-325 mg and clopidogrel 300-600 mg on Day 1 7, 8
• The maintenance dose is aspirin 75-100 mg daily and clopidogrel 75 mg daily for Days 2-21 7, 8
• After Day 21, patients should transition to single antiplatelet therapy with either aspirin 75-100 mg daily or clopidogrel 75 mg daily 7, 8

Critical Timing Considerations

• DAPT must be started as early as possible, ideally within 12 hours of symptom onset, to maximize benefit 7, 8
• The benefit of DAPT is confined to the first 21 days, with most stroke prevention occurring in the first week 8
• Continuing DAPT beyond 21-30 days significantly increases major hemorrhage risk without additional benefit 8, 9

Safety Monitoring

• The risk of major hemorrhage increases with DAPT (RR 1.88-1.90) compared to aspirin alone 9
• Gastroprotection with proton pump inhibitors should be considered in patients with gastrointestinal bleeding risk factors 9
• Patients should be monitored for signs of intracranial or systemic bleeding during the 21-day treatment period 7

Common Pitfalls to Avoid

• DAPT should not be used as a substitute for thrombolysis or thrombectomy in eligible patients 8
• DAPT should not be continued beyond 30 days as bleeding risk outweighs benefit 7, 8, 9
• Enteric-coated aspirin should not be used for loading dose due to slower onset of action 8
• Initiation of DAPT should not be delayed beyond 24 hours as efficacy is time-dependent 7, 8