Does a Posterior Cerebral Artery (PCA) infarct require dual antiplatelet therapy (DAPT)?

Dual Antiplatelet Therapy for PCA Infarct

A posterior cerebral artery (PCA) infarct does NOT require dual antiplatelet therapy (DAPT) as standard treatment; single antiplatelet therapy is the recommended approach for secondary stroke prevention in noncardioembolic ischemic stroke, including PCI territory infarcts. 1

Evidence-Based Rationale

The question of DAPT for PCA infarcts must be distinguished from coronary artery disease management, where DAPT plays a central role. For ischemic stroke:

Standard Treatment for Ischemic Stroke

• Single antiplatelet therapy is the standard of care for secondary prevention after ischemic stroke, regardless of whether the infarct involves anterior or posterior circulation territories 1

• Recent real-world evidence demonstrates that DAPT outcomes in mild-to-moderate noncardioembolic stroke are consistent between PCI and anterior circulation infarcts, with similar 90-day risks of recurrent ischemic stroke or vascular events (3.1% vs 2.9%) 1

When DAPT May Be Considered in Stroke

DAPT is only indicated in highly specific stroke scenarios:

• Minor ischemic stroke (NIHSS 0-3) or high-risk TIA initiated within 24-48 hours of symptom onset, typically for 21-90 days 1

• Mild-to-moderate stroke (NIHSS 0-10) with noncardioembolic etiology, particularly when initiated within 48 hours 1

• The location in posterior versus anterior circulation does not change the indication for DAPT 1

Safety Profile

• Safety outcomes with DAPT in stroke patients show low bleeding rates (any bleeding 3.2% in PCI vs 2.6% in anterior circulation; hemorrhagic transformation 1.8% vs 1.2%) 1

• These rates are acceptable when DAPT is appropriately indicated, but do not justify routine use in all stroke patients 1

Important Caveats

Do not confuse this with coronary disease management: The evidence provided about DAPT in coronary artery disease 2, 3, 4, 5, 6, 7 and peripheral artery disease 2 is not applicable to cerebrovascular stroke management. A PCA infarct refers to posterior cerebral artery stroke, not posterior coronary artery.

Functional outcomes may differ: Patients with PCI had worse 90-day modified Rankin Scale distribution compared to anterior circulation infarcts (OR 1.18), suggesting posterior circulation strokes may have worse functional recovery despite similar recurrent event rates 1

Clinical Algorithm for PCA Infarct

1. Assess stroke severity: NIHSS score and timing from symptom onset 1

2. Determine etiology: Rule out cardioembolic sources (atrial fibrillation, cardiac thrombus) 1

3. For minor stroke (NIHSS 0-3) within 24-48 hours: Consider short-term DAPT (21-90 days) 1

4. For all other PCA infarcts: Use single antiplatelet therapy (aspirin or clopidogrel) 1

5. Never use DAPT routinely based solely on posterior circulation location 1