What are the target systolic blood pressure (SBP) and mean arterial pressure (MAP) in acute infarct in the left Middle Cerebral Artery (MCA) territory?

Blood Pressure Management in Acute Ischemic Stroke of Left MCA Territory

For patients with acute ischemic stroke in the left MCA territory who are not receiving reperfusion therapy, blood pressure should not be actively lowered unless it exceeds 220/120 mmHg, in which case it should be carefully reduced by approximately 15% during the first 24 hours after stroke onset. 1, 2

BP Management Based on Treatment Status

For Patients NOT Receiving Reperfusion Therapy:

• If BP <220/120 mmHg: No antihypertensive treatment is recommended during the first 48-72 hours 3, 1
• If BP ≥220/120 mmHg: Carefully lower BP by approximately 15% during the first 24 hours 3, 1
• Rationale: Cerebral autoregulation in the ischemic penumbra is impaired, making cerebral perfusion directly dependent on systemic blood pressure 1, 4

For Patients Receiving Reperfusion Therapy:

• Before thrombolysis: Lower BP to <185/110 mmHg 3
• During and after thrombolysis: Maintain BP <180/105 mmHg for at least the first 24 hours 3
• Monitor BP every 15 minutes for 2 hours from the start of rtPA therapy, then every 30 minutes for 6 hours, and then every hour for 16 hours 3

Timing of Antihypertensive Therapy Initiation

• For patients with BP <180/105 mmHg: No benefit from introducing or reintroducing BP-lowering medication in the first 72 hours 3, 1
• For stable patients who remain hypertensive (≥140/90 mmHg): Initiate or reintroduce BP-lowering medication ≥3 days after stroke onset 3
• Starting or restarting antihypertensive therapy during hospitalization is reasonable in neurologically stable patients with BP >140/90 mmHg to improve long-term BP control 3

Pharmacological Considerations

• When BP reduction is necessary, preferred agents include: 3, 1
  • Labetalol: 10 mg IV followed by continuous IV infusion 2-8 mg/min
  • Nicardipine: 5 mg/h IV, titrate up by 2.5 mg/h every 5-15 minutes, maximum 15 mg/h
• Avoid sodium nitroprusside due to its adverse effects on cerebral autoregulation and intracranial pressure 4

Special Considerations for MCA Territory Infarcts

• Large MCA infarcts are associated with higher mortality (17%) and severe disability (50%) compared to other infarct types 5
• In MCA territory strokes, cerebral perfusion correlates more strongly with cardiac index than with MAP, suggesting that optimizing cardiac output might be valuable for maintaining penumbral perfusion 6
• Patients with severe MCA atherosclerotic disease often have borderzone infarcts due to hemodynamic insufficiency, highlighting the importance of maintaining adequate perfusion pressure 7

Common Pitfalls to Avoid

• Lowering BP too aggressively in the acute phase can compromise collateral perfusion of the ischemic penumbra 3, 1
• Excessive acute drops in systolic BP (>70 mmHg) may cause acute renal injury and early neurological deterioration 3, 8
• Neglecting to restart antihypertensive medications after the acute phase (≥3 days) in patients with pre-existing hypertension 3, 1
• Treating BP <220/120 mmHg in the first 48-72 hours in patients not receiving thrombolysis, which has been shown to be ineffective for preventing death or dependency 3, 1

Long-term BP Management After Acute Phase

• For patients with ischemic stroke and an indication for BP lowering, antihypertensive therapy should be commenced before hospital discharge 3, 1
• BP targets for secondary stroke prevention may be lower (<130/80 mmHg) after the acute phase has resolved 3, 1