What is the antiplatelet plan for a patient with a large acute left Middle Cerebral Artery (MCA) infarction complicated by hemorrhagic conversion and 67% stenosis of the left Internal Carotid Artery (ICA)?

Antiplatelet Management in Large MCA Infarction with Hemorrhagic Conversion and Significant ICA Stenosis

Immediate Management: Hold All Antiplatelet Therapy

In a patient with large acute left MCA infarction complicated by hemorrhagic conversion, all antiplatelet therapy must be immediately withheld regardless of the 67% left ICA stenosis, as the acute bleeding risk substantially outweighs any potential ischemic benefit in the hyperacute phase. 1

• The presence of hemorrhagic transformation represents active intracranial bleeding, which is an absolute contraindication to antiplatelet therapy in the acute setting 2
• The 67% ICA stenosis, while significant, does not meet the threshold for urgent revascularization (<70% stenosis) and can be managed medically once the hemorrhagic risk stabilizes 3, 4

Timing of Antiplatelet Resumption

Early Phase (First 24-72 Hours)

• Maintain antiplatelet avoidance for at least 24 hours after hemorrhagic conversion is identified 1
• Obtain repeat neuroimaging (CT or MRI) to assess hemorrhage stability and expansion before considering any antiplatelet therapy 5
• Monitor neurological status closely for signs of hemorrhage expansion or new ischemic events 5

Subacute Phase (Days 3-14)

Resumption of antiplatelet monotherapy may be reasonable after 24-72 hours if repeat imaging demonstrates stable hemorrhagic transformation without expansion and the patient has a compelling indication for antiplatelet therapy (the 67% ICA stenosis qualifies as such an indication). 1

• The RESTART trial demonstrated that starting antiplatelet therapy after ICH did not increase recurrent hemorrhage risk (adjusted HR 0.51,95% CI 0.25-1.03) and may reduce major adverse cardiovascular events 1
• Canadian guidelines (Level B evidence) state that "in patients with an indication for continued antiplatelet treatment, resuming antiplatelet therapy is reasonable" 1
• US guidelines (Level B-R evidence) indicate that "resumption of antiplatelet therapy may be reasonable for the prevention of thromboembolic events based on consideration of benefit and risk" 1
• Chinese guidelines recommend that "aspirin monotherapy can be restored within a few days from the onset of ICH, but the best timing is not clear" 1

Specific Antiplatelet Regimen

Start with aspirin 75-100 mg daily as monotherapy 3, 6

• Aspirin monotherapy is preferred over clopidogrel initially given the established safety profile and lower cost 1, 6
• Avoid dual antiplatelet therapy (DAPT) in the setting of recent hemorrhagic conversion, as the bleeding risk is prohibitive 1, 7
• Do NOT use a loading dose of any antiplatelet agent given the recent hemorrhagic conversion 2

Management of the 67% ICA Stenosis

Medical Management is Primary

The 67% ICA stenosis should be managed with optimal medical therapy rather than revascularization, as stenosis <70% does not meet criteria for carotid endarterectomy or stenting. 3, 4

• Revascularization (CEA or CAS) is explicitly NOT indicated for stenosis <70% (Class III, Level A evidence) 3
• Once antiplatelet therapy is safely resumed, continue aspirin 75-100 mg daily indefinitely 3, 6
• Initiate high-intensity statin therapy immediately (this can be started even during the antiplatelet hold period) targeting LDL <55 mg/dL 4
• Aggressive blood pressure control, smoking cessation, and diabetes management are essential 3

Surveillance Strategy

• Perform duplex ultrasound at 3-6 months to assess for stenosis progression 3
• If stenosis progresses to ≥70% and becomes symptomatic, reconsider revascularization options at that time 4
• Annual follow-up with vascular imaging is recommended 3

Critical Decision-Making Algorithm

Step 1: Confirm hemorrhagic conversion on imaging → Hold all antiplatelets immediately 1, 2

Step 2: Repeat imaging at 24-48 hours → Assess hemorrhage stability 5

Step 3: If hemorrhage is stable and not expanding → Consider aspirin 75-100 mg daily starting day 3-7 1, 6

Step 4: Continue aspirin monotherapy long-term for the ICA stenosis → No revascularization needed for 67% stenosis 3, 4

Step 5: Add high-intensity statin, optimize blood pressure, and arrange vascular follow-up 3, 4

Common Pitfalls to Avoid

• Do not restart antiplatelet therapy within the first 24 hours of hemorrhagic conversion identification - this significantly increases the risk of hemorrhage expansion 1
• Do not use dual antiplatelet therapy (aspirin + clopidogrel) in this setting - the bleeding risk far outweighs any ischemic benefit given the recent hemorrhagic conversion 1, 7
• Do not pursue carotid revascularization for 67% stenosis - this is below the threshold for intervention and medical management is superior 3, 4
• Do not administer loading doses of antiplatelet agents when restarting therapy after hemorrhagic conversion - use maintenance dosing only 2
• Do not assume the patient needs urgent carotid stenting - the acute stroke with hemorrhagic conversion makes any intervention requiring antiplatelet therapy extremely high risk 1, 8, 9

Special Considerations for This Case

• The combination of large MCA infarction with hemorrhagic conversion creates a particularly high-risk scenario where the bleeding risk temporarily supersedes the ischemic risk from the ICA stenosis 5, 10
• If the patient were to require urgent carotid intervention (which is NOT indicated at 67% stenosis), techniques that avoid stenting and thus avoid mandatory DAPT could be considered, but this is not applicable to this patient 9
• The patient will require lifelong antiplatelet monotherapy once safely restarted, given the atherosclerotic disease burden 3, 6