Blood pressure and functional recovery in acute ischemic stroke

Abstract

Background and purpose: The relevance of elevated blood pressure in acute ischemic stroke and its most appropriate management are unresolved. We aimed to evaluate the rate of functional recovery with relation to early blood pressure management in patients with ischemic stroke.

Methods: Four hundred eighty-one consecutive ischemic stroke patients were admitted to the Neurology Service within 20.9+/-10.5 hours of symptoms onset as part of the Barcelona Downtown Stroke Registry, including 235 patients who received oral antihypertensive agents within <24 hours after stroke onset. Demographic, clinical (Mathew scale), and CT scan findings were collected prospectively. Mean arterial pressure (MAP) was recorded before hospital arrival and at 7 AM on days 1, 2, and 7 of hospitalization. The primary end point was complete functional recovery at day 7 defined as a score of 0 to 1 on the modified Rankin scale.

Results: Two hundred fifty-two patients achieved complete recovery on day 7. Using logistic regression, independent predictors of complete recovery included mild impairment at stroke presentation, lack of history of hypertension, and absence of brain edema on CT scan. Also, a 20% to 30% drop in MAP on day 2 after stroke onset almost tripled the odds of full recovery (odds ratio, 2.9; 95% CI, 1.3 to 6.3). MAP tended to normalize after stroke in all subjects, more rapidly if hypotensive agents were administered. Brain edema was also less frequent in patients with a greater drop in blood pressure. Despite the fact that a drop in MAP >30% from baseline was observed in 49 patients, this preceded worsening stroke in only 4 patients. Conversely, worsening stroke occurred in 51 patients despite stable blood pressure.

Conclusions: These results suggest that complete recovery in ischemic stroke is facilitated by a moderate blood pressure reduction when brain edema develops, most likely as the result of a more adequate cerebral perfusion pressure. Conversely, stroke worsening due to pharmacological hypoperfusion is exceptional.