What is the management plan for a patient with polycythemia vera and a history of smoking who presents with a brain MRI showing a single focus of acute ischemia involving the right posterior body of the corpus callosum?

Management of Acute Ischemic Stroke in a Patient with Polycythemia Vera

For a patient with polycythemia vera and smoking history presenting with a brain MRI showing a single focus of acute ischemia in the right posterior corpus callosum, immediate initiation of oral aspirin 325 mg is recommended, along with aggressive management of the underlying polycythemia vera to prevent further thrombotic events. 1

Initial Management of Acute Ischemic Stroke

Immediate Antiplatelet Therapy

• Administer aspirin 325 mg orally within 24-48 hours of stroke onset 1
• Do not substitute aspirin for other acute interventions such as intravenous rtPA if the patient is eligible 1
• Avoid combining aspirin with other antiplatelet agents in the acute setting 1

Blood Pressure Management

• Monitor blood pressure frequently during the first 24 hours
• For patients without indication for thrombolytic therapy:
  • Allow permissive hypertension in the first 24-48 hours unless BP exceeds 220/120 mmHg 1
  • Avoid aggressive BP lowering during the acute phase as it may compromise cerebral perfusion to the penumbra

Specific Management for Polycythemia Vera

Immediate Interventions

• Initiate phlebotomy to maintain hematocrit <45% for men and <42% for women 2, 3
• This is the cornerstone treatment for reducing mortality and morbidity in PV patients

Antiplatelet Therapy

• Continue daily low-dose aspirin (75-100 mg) after the initial 325 mg dose 3, 4
• Monitor for bleeding complications, especially if platelet count is elevated >600×10^9/L 5

Cytoreductive Therapy

• For high-risk PV patients (age >60 years or history of thrombosis), initiate cytoreductive therapy 6, 3
• First-line: Hydroxyurea
• Second-line options: Interferon-α or busulfan 3

Risk Factor Modification

Smoking Cessation

• Strongly advise immediate smoking cessation 1
• Offer smoking cessation interventions and support
• Smoking significantly increases thrombotic risk in patients with PV 6

Lipid Management

• Initiate statin therapy to reduce LDL cholesterol to <70 mg/dL 1
• Statins have shown benefit in patients with ischemic stroke regardless of baseline cholesterol levels

Follow-up Imaging and Monitoring

• Schedule follow-up brain MRI in 4-6 weeks to assess evolution of the ischemic lesion
• Monitor complete blood count weekly initially, then monthly once stable
• Adjust phlebotomy schedule based on hematocrit levels

Potential Pitfalls and Caveats

1. Dual antiplatelet/anticoagulant therapy risks: Combining aspirin with anticoagulants in PV patients increases hemorrhage risk nearly 6-fold (HR: 5.83) 5

2. Thrombocytosis monitoring: Periods of thrombocytosis (>600×10^9/L) increase hemorrhage risk (HR: 2.25) 5

3. Induced hypertension: While some studies suggest potential benefit of induced hypertension in acute stroke, this approach is not well-established and should only be considered in clinical trials 1

4. Vasodilator medications: Avoid vasodilatory agents such as pentoxifylline as they have not shown benefit in acute ischemic stroke 1

By following this approach, you can optimize management of this patient's acute ischemic stroke while addressing the underlying polycythemia vera to prevent future thrombotic events and minimize bleeding complications.