When to maintain mean arterial pressure (MAP) versus systolic blood pressure (SBP) in acute stroke management?

Blood Pressure Management in Acute Ischemic Stroke: MAP vs SBP Targets

In acute ischemic stroke, use SBP targets for patients receiving reperfusion therapy and consider MAP reduction (by 15%) only for patients with extremely elevated blood pressure (>220/120 mmHg) who are not receiving reperfusion therapy. 1, 2

Blood Pressure Management Based on Treatment Status

Patients Receiving Reperfusion Therapy (IV Thrombolysis/Thrombectomy)

• SBP should be lowered to <185 mmHg and DBP <110 mmHg before initiating IV thrombolysis 1, 2
• After thrombolysis or thrombectomy, maintain SBP <180 mmHg and DBP <105 mmHg for at least the first 24 hours 1, 2
• These specific SBP targets correspond to pivotal clinical trials of intravenous thrombolysis for acute ischemic stroke 1
• Failure to control BP in this range increases risk of symptomatic intracranial hemorrhage 1, 2

Patients NOT Receiving Reperfusion Therapy

• If BP <220/120 mmHg: No antihypertensive treatment is recommended during the first 48-72 hours 1, 2
• If BP ≥220/120 mmHg: Use MAP reduction target of 15% during the first 24 hours 1, 2
• Initiating or reinitiating treatment of hypertension within the first 48-72 hours after stroke is not effective to prevent death or dependency in patients with BP <220/120 mmHg 1, 2

Rationale for Different Approaches

• Why MAP for severe hypertension without reperfusion: MAP reduction by 15-20% is recommended because:

  • It provides a more controlled reduction that preserves cerebral perfusion 1, 3
  • Cerebral autoregulation is impaired in the ischemic penumbra 1, 2
  • Systemic perfusion pressure is needed for blood flow and oxygen delivery 1

• Why SBP for reperfusion therapy: Specific SBP targets are used because:

  • These thresholds were established in pivotal clinical trials of thrombolysis 1, 2
  • Higher BP increases risk of hemorrhagic transformation after reperfusion 1, 3
  • More precise control is needed to balance reperfusion benefits against bleeding risks 2

Timing of BP Management

• Acute phase (first 24-72 hours):

  • Conservative approach for patients not receiving reperfusion therapy 1, 2
  • More aggressive approach for patients receiving reperfusion therapy 1

• After 3 days:

  • For stable patients who remain hypertensive (≥140/90 mmHg), initiate or reintroduce BP-lowering medication 1, 4
  • Antihypertensive therapy should be commenced before hospital discharge 1, 4

Pharmacological Considerations

• First-line agents when BP lowering is indicated:

  • Labetalol is preferred for BP control in acute ischemic stroke 1, 2, 5
  • Nicardipine is an effective alternative 1, 2, 6
  • Avoid sodium nitroprusside due to its adverse effects on cerebral autoregulation and intracranial pressure 6

• Administration considerations:

  • When using MAP targets, aim for a controlled reduction of 15% over several hours 1, 5
  • Avoid excessive BP drops (>70 mmHg) as this may cause acute renal injury and neurological deterioration 1, 2

Common Pitfalls to Avoid

• Lowering BP too aggressively in patients not receiving reperfusion therapy, which can compromise cerebral perfusion 1, 2
• Treating BP <220/120 mmHg in the first 48-72 hours in patients not receiving thrombolysis 1, 2
• Failing to monitor BP frequently during the first 24 hours to identify trends requiring intervention 1
• Neglecting to restart antihypertensive medications after the acute phase (≥3 days) in patients with pre-existing hypertension 1, 4

Special Considerations

• Studies have shown a U-shaped relationship between admission BP and outcomes, with optimal SBP ranging from 121-200 mmHg and DBP from 81-110 mmHg 1, 7
• Both hypertension and hypotension are associated with poor outcomes in acute ischemic stroke 1, 8
• Patients are often volume depleted due to pressure natriuresis; intravenous saline may be needed to prevent precipitous BP falls 1