What are the guidelines for managing permissive hypertension (HTN) following an ischemic cerebrovascular accident (CVA)?

From the Guidelines

Permissive hypertension management following an ischemic stroke involves allowing elevated blood pressure temporarily to maintain cerebral perfusion, with treatment generally not initiated unless blood pressure exceeds 220/120 mmHg for patients not receiving thrombolytic therapy, or maintained below 180/105 mmHg for the first 24 hours in patients who received thrombolytic therapy, as recommended by the 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline 1.

Key Considerations

• For patients eligible for intravenous tissue plasminogen activator, blood pressure should be slowly lowered to less than 185/110 mm Hg before thrombolytic therapy is initiated, and maintained below 180/105 mm Hg for at least the first 24 hours after initiating drug therapy 1.
• In patients with blood pressure of 220/120 mm Hg or higher who did not receive intravenous alteplase or endovascular treatment and have no comorbid conditions requiring acute antihypertensive treatment, the benefit of initiating or reinitiating treatment of hypertension within the first 48 to 72 hours is uncertain, but it might be reasonable to lower blood pressure by 15% during the first 24 hours after onset of stroke 1.
• If treatment is needed, intravenous medications with short half-lives, such as labetalol, nicardipine, or clevidipine, are preferred, with blood pressure lowered gradually, aiming for a 15-25% reduction in the first 24 hours rather than normalizing it immediately.

Management Approach

• The permissive approach is based on the concept of the ischemic penumbra—tissue surrounding the infarct core that remains viable but at risk, where higher blood pressure helps maintain perfusion to this at-risk tissue until collateral circulation develops.
• Aggressive blood pressure reduction early after stroke can expand the infarct size by reducing blood flow to the penumbra, potentially worsening neurological outcomes.
• After 48-72 hours, gradual transition to oral antihypertensives can begin, with the goal of improving long-term blood pressure control, unless contraindicated 1.

From the Research

Guidelines for Managing Permissive Hypertension Following Ischemic CVA

The management of permissive hypertension following an ischemic cerebrovascular accident (CVA) is crucial to prevent further brain damage. The guidelines for managing permissive hypertension are as follows:

• Blood pressure should not be treated unless the systolic pressure exceeds 220 mm Hg or the diastolic pressure exceeds 120 mm Hg 2, 3, 4
• In patients undergoing intravenous thrombolysis for acute ischemic stroke, blood pressure should be reduced and maintained below 185 mm Hg systolic for the first 24 hours 3, 4
• Labetalol, nicardipine, and hydralazine are recommended for lowering blood pressure in acute ischemic stroke patients 4, 5
• Sodium nitroprusside is not recommended due to its adverse effects on cerebral autoregulation and intracranial pressure 2

Blood Pressure Targets

The optimal blood pressure targets for patients with permissive hypertension following ischemic CVA are:

• Systolic blood pressure < 220 mm Hg and diastolic blood pressure < 120 mm Hg for patients not undergoing thrombolysis 2, 3, 4
• Systolic blood pressure < 185 mm Hg and diastolic blood pressure < 110 mm Hg for patients undergoing thrombolysis 3, 4
• Systolic blood pressure < 180 mm Hg and diastolic blood pressure < 105 mm Hg after successful reperfusion therapy 3

Antihypertensive Agents

The choice of antihypertensive agent for managing permissive hypertension following ischemic CVA is:

• Labetalol, nicardipine, and hydralazine are recommended as first-line agents 4, 5
• Nicardipine may cause an excessive fall in blood pressure and impair cerebral blood flow, and should be used with caution 6