A pilot study of ambulatory blood pressure monitoring and its prognostic value in acute ischemic stroke

Objective To evaluate blood pressure changes in the acute phase of cerebral infarction and the relationship between BP and early or late neurological outcome.Methods Fifty-three patients admitted within 48 hours of stroke onset were studied prospectively.Blood pressures were collected by monitoring for 10 days.The other prognostic factors were recorded through detailed investigation.The early and late outcomes were assessed 21 days and 3 months after stroke onset and were defined as modified ranking scale score ≥3.Results The elevated blood pressure after acute ischemic stroke declined spontaneously.After 4 days SBP and DBP declined by(8.8±7.9) mm Hg/(4.5±5.0) mm Hg(P0.05).From the 4th to 10th day,BP still declined slightly though not significantly.A u-shaped relationship was observed between blood pressure and late outcome in acute ischemic stroke.The blood pressure level for the lowest frequency of poor outcome was 140～160 mm Hg(SBP) and 75～80 mm Hg(DBP).However,after adjusting other prognostic factors,only SBP≥160 mm Hg showed a significant relationship with poor outcome in logistic regression.For every 10mmHg above 160 mm Hg,the risk of early and late poor outcome increased by 368.2% and 137.2%.Conclusions Elevated blood pressure was common in acute ischemic stroke.However it declined spontaneously 4 to 10 days after stroke.A significantly elevated blood pressure(SBP≥160 mm Hg) usually indicates a poor neurological outcome.