Management of blood pressure after acute stroke

Article 1
Article section 1 of 3.  Next

By Douglas J Lanska MD MS MSPH

Article under review:

Aiyagari V, Gorelick PB. Management of blood pressure for acute and recurrent stroke. Stroke 2009;40(6):2251-6.

Background: Hypertension is the most important modifiable risk factor for stroke, but the management of blood pressure immediately after a stroke is controversial. It requires balancing the protective benefit of lowering blood pressure (eg, on de novo or expanding hemorrhage) with the potential harm to the dysfunctional but not dead brain tissue surrounding the area of hemorrhage ("perihematomal ischemic zone") or ischemic stroke ("ischemic penumbra"). Normally, cerebrovascular autoregulation serves to maintain stable blood flow over a considerable range of blood pressures, but when autoregulation becomes dysfunctional in the perihematomal ischemic zone or ischemic penumbra, blood flow to the damaged area becomes directly dependent on blood pressure. Thus, lowering blood pressure too aggressively after a stroke can serve to shunt too much blood away from the damaged area, leading potentially to further damage of brain tissue that otherwise might have recovered (Fischberg et al 2000).

Purpose: To review recommended management approaches and summarize current American Heart Association and American Stroke Association guidelines for blood pressure management after stroke.

Methods: Review.

Results/Conclusions:

Blood pressure management after acute intracerebral hemorrhage:

  • If SBP > 200 mm Hg (or MAP > 150 mm Hg), then aggressively lower BP.
  • If SBP > 180 mm Hg (or MAP > 130 mm Hg):
    - If ICP is possibly elevated, then consider ICP monitoring and reducing BP to maintain a cerebral perfusion pressure of 60 to 80 mm Hg.
    - If there is no clinical evidence or suspicion of elevated ICP, then reduce BP to target BP of 160/90 mm Hg (or target MAP of 110 mm Hg).
  • Lower BP targets may be appropriate in specific clinical settings, eg, hypertensive encephalopathy, congestive heart failure, or acute cardiac ischemia.
  • Lower MAP by no more than 20% in the first 24 hours to avoid lowering CBF.
  • Preferentially utilize rapidly acting intravenous antihypertensive agents with a short half-life.
    - In the United States, recommended antihypertensive agents for management of acute intracerebral hemorrhage include enalapril, esmolol, hydralazine, labetalol, nicardipine, nitroglycerine, and nitroprusside. Nitroglycerine and nitroprusside should be used with caution in this setting because they can potentially increase ICP.
    - In Europe, intravenous urapidil is also recommended.

Blood pressure management after acute ischemic stroke:

  • For patients eligible for intravenous thrombolytic therapy or other reperfusion therapy and whose SBP > 185 mm Hg or DBP > 110 mm Hg, BP must be lowered before reperfusion therapy can be given. After reperfusion therapy, maintain SBP < 180 mm Hg and DBP < 105 mm Hg for at least 24 hours.
  • For patients not receiving thrombolytic therapy and whose BP is markedly elevated to levels of SBP > 220 mm Hg or DBP > 120 mm Hg, lower MAP by ~15% in the first 24 hours.
  • Lower BP if there are other medical indications that require this, eg, acute heart failure or aortic dissection.
  • For lower levels of BP elevation, it is not clear whether patients who had been on antihypertensive medications should have their BP medications withheld or continued, but certainly no aggressive lowering of BP to "normal" levels should be attempted. If antihypertensive medications are withheld, they should be restarted in neurologically stable patients at 24 hours unless otherwise contraindicated.
  • Volume expansion and/or vasopressors may be used to try to improve CBF in patients with hypotensive stroke or in patients whose neurologic deficits worsened with a drop in BP.

Blood pressure management for prevention of recurrent stroke:

  • Start oral antihypertensive medications 24 to 72 hours after onset of acute ischemic stroke symptoms unless otherwise contraindicated (eg, presumed hemodynamic mechanism of stroke).
  • BP lowering of at least 10/5 mm Hg is beneficial.
  • Target BP < 140/90 mm Hg for patients with uncomplicated hypertension and < 130/80 mm Hg for patients with diabetes or chronic kidney disease.
  • Although the degree of BP lowering appears to be more important than the agent used for most patients, the choice of an antihypertensive agent should take into account the patient's associated medical conditions (eg, patients with the "metabolic syndrome" are not good candidates for beta-blockers). Consider a thiazide diuretic or a thiazide diuretic in combination with an angiotensin-converting enzyme inhibitor.

Abbreviations: BP = blood pressure; CBF = cerebral blood flow; DBP = diastolic blood pressure; ICP = intracranial pressure; MAP = mean arterial pressure; SBP = systolic blood pressure.