Target Mean Arterial Pressure in Acute Ischemic Stroke Without Thrombolysis
In adults with acute ischemic stroke not receiving reperfusion therapy, do not treat blood pressure unless it exceeds 220/120 mmHg (MAP ~153 mmHg) during the first 48–72 hours; if treatment is required at this threshold, reduce MAP by only 15% over 24 hours (from ~153 to ~130 mmHg). 1
Blood Pressure Management Algorithm
First 48–72 Hours: Permissive Hypertension Phase
Do not initiate or restart antihypertensive medications when systolic BP is <220 mmHg or diastolic <120 mmHg (MAP <153 mmHg), as this approach does not reduce death or dependency and may worsen outcomes by compromising cerebral perfusion to the ischemic penumbra. 1 This is a Class III (No Benefit) recommendation from the ACC/AHA. 1
Optimal MAP range during permissive hypertension: Approximately 90–140 mmHg (corresponding to systolic 121–200 mmHg), based on observational data showing a U-shaped relationship between admission blood pressure and mortality. 2, 3
Physiologic rationale: Cerebral autoregulation is grossly impaired in the ischemic penumbra, making cerebral blood flow directly dependent on systemic perfusion pressure; aggressive BP lowering can extend infarct size by reducing oxygen delivery to salvageable brain tissue. 1, 2
When MAP ≥153 mmHg (BP ≥220/120 mmHg)
Reduce MAP by only 15% over the first 24 hours (e.g., from 153 mmHg to ~130 mmHg). 1, 2 This is a Class IIb recommendation. 1
Preferred IV agents for controlled reduction:
Avoid precipitous drops: Reductions >70 mmHg can precipitate cerebral, renal, or coronary ischemia. 2, 4
Never use sublingual nifedipine: This agent cannot be titrated and causes unpredictable, dangerous drops in cerebral perfusion. 2
After 48–72 Hours: Transition to Secondary Prevention
Restart antihypertensive therapy in neurologically stable patients with BP ≥140/90 mmHg (MAP ≥93 mmHg). 1, 5 This is a Class IIa recommendation. 1
Long-term target: MAP corresponding to BP <130/80 mmHg for secondary stroke prevention. 2, 5
Preferred agents: Thiazide diuretics, ACE inhibitors, ARBs, or combination therapy (thiazide plus ACE inhibitor). 5, 6
Critical Exceptions Requiring Immediate BP Control
Override permissive hypertension guidelines and treat BP immediately in these conditions, regardless of the 48–72 hour window: 1, 2
- Hypertensive encephalopathy
- Acute aortic dissection
- Acute myocardial infarction
- Acute pulmonary edema
- Acute renal failure
Management of Hypotension
Hypotension is more dangerous than hypertension in acute stroke and requires urgent correction with fluids or vasopressors to maintain adequate cerebral perfusion. 2, 7
Target MAP >70 mmHg if hypotension develops, with close neurological monitoring. 8
Common Pitfalls to Avoid
Do not reflexively treat elevated BP during the first 48–72 hours; the elevation often represents a compensatory response to maintain cerebral perfusion to the penumbra. 2, 4
Do not automatically restart home antihypertensives during the permissive phase unless specific comorbid conditions mandate treatment. 2, 5
Avoid rapid titration: Even lowering BP to levels within the hypertensive range can be detrimental if done too quickly, as the ischemic brain cannot compensate for sudden pressure changes. 2, 4
Monitor for neurological deterioration with each BP measurement; worsening symptoms may indicate compromised penumbral perfusion requiring BP augmentation. 6
Evidence Quality and Nuances
The permissive hypertension strategy is supported by Class III (No Benefit) evidence from the 2017 ACC/AHA guidelines, indicating that two RCTs plus systematic reviews and meta-analyses found no benefit—and potential harm—from lowering BP <220/120 mmHg during the acute phase. 1 The 15% reduction threshold for extreme hypertension (≥220/120 mmHg) is based on Class IIb (uncertain benefit) evidence and expert consensus, reflecting the balance between preventing hypertensive complications and maintaining penumbral perfusion. 1, 3, 4