Blood pressure decrease during the acute phase of ischemic stroke is associated with brain injury and poor stroke outcome

Background and Purpose - Studies on the relation between blood pressure ( BP) and stroke outcome have shown contradictory results. We explored the association of systolic (SBP) and diastolic (DBP) BP during acute stroke with early neurological deterioration, infarct volume, neurological outcome, and mortality at 3 months. Methods - We included 304 patients with acute ischemic stroke. SBP and DBP on admission and on the first day were the average values of all readings obtained in the emergency department and during a 24-hour period after patient allocation in the stroke unit. Results - A U-shaped effect was observed: for every 10 mm Hg less than or equal to 180 mm Hg of SBP, the risk of early neurological deterioration, poor outcome, and mortality increased by 6%, 25%, and 7%, respectively, whereas for every 10 mm Hg > 180 mm Hg, the risk of early neurological deterioration increased by 40% and the risk of poor outcome increased by 23%, with no effect on mortality. Mean infarct volume increased 7.3 and 5.5 cm(3) for every 10 mm Hg less than or equal to 180 and > 180 mm Hg. A similar pattern was found in patients with DBP less than or equal to 100 or > 100 mm Hg. These effects disappeared after adjustment for the use of antihypertensive drugs and BP drop > 20 mm Hg within the first day, with the latter being the more important prognostic factor of poor outcome. Conclusions - High and low SBP and DBP, as well as a relevant drop in BP, are associated with poor prognosis in patients with ischemic stroke.