Evaluating the Influence of Day-to-day Blood Pressure Variation in Acute Ischemic Stroke on Adverse Outcomes in Long-term Post-stroke Followup

System hypertension has been reported to play the most important role in the development of stroke,and the anti-hypertension therapy is regarded as the cornerstone for stroke secondary prevention. However, even though some proper measures have been taken,there is still surplus risk for recurrent stroke. Recently the variation of system blood pressure has been focused as the candidate of another risk factor.Up to date,this hypothesis remains an intense debate and few studies has been done to clarify it.Besides, the definition of BPV and measurement of BPV parameters are still beyond conformity.In the current study, the long-term and short-term BPV will be taken respectively for patients with prior stroke. Bsed on these parameters, the cohort will be followed up for average 2 years. The predefined outcome include composite cardiovascular events, neuropsychiatric wording, and mortality during followup.