Effect Of Blood Pressure Reduction In The Acute Phase Of Ischemic Stroke: A Meta-analysis

The incidence of cerebrovascular disease increased year by year, many patients will be left a permanent disability or directly lead to death. Ischemic stroke accounted for about 85% of all the stroke types. Thus, to improve the quality of life and reduce the disability, corresponding treatment is very important, especially in the early time of ischemic stroke. The management of patients’ blood pressure can not be ignored in the process of treatment. In the acute phase of ischemic storke, many patients have a hypertension or blood pressure elevated. The level of blood pressure in acute ischemic stroke is close related with the progress of the stroke, transformation, outcome and prognosis. Higher blood pressure may aggravate cerebral edema、increase the risk of hemorrhage transformation. So we should actively control the blood pressure in acute ischemic stroke. But there are also studies show that reduce blood pressure in acute ischemic stroke is significantly associate with a poor prognosis[1,2], the mechanism is stroke damage the autoregulate of the cerebrovascular, when the blood pressure lower, the cerebral blood flow will decreased, the ischemic penumbra range will increased and the symptom increased[3]. So some people have an opposite idea of use antihypertensive in the acute phase of ischemic stroke. Currently used to guide the clinical treatment of the AHA/ASA 2014 stroke secondary prevention guide poined out [4]: initiation of BP therapy is indicated for previously untreated patients with ischemic stroke, after the first several days, have an established BP ≥140 mm Hg systolic or ≥90 mm Hg diastolic(Class I; Level of Evidence B). Initiation of therapy for patients with BP <140 mm Hg systolic and <90 mm Hg diastolic is of uncertain benefit(Class IIb; Level of Evidence C). Resumption of BP therapy is indicated for previously treated patients with known hypertension for both prevention of recurrent stroke and prevention of other vascular events in those who have had an ischemic stroke and are beyond the first several days(Class I; Level of Evidence A). Goals for target BP level or reduction from pretreatment baseline are uncertain and should be individualized, but it is reasonable to achieve a systolic pressure <140 mm Hg and a diastolic pressure <90 mm Hg(Class IIa; Level of Evidence B). For patients with a recent lacunar stroke, it might be reasonable to target a systolic BP of <130 mm Hg(Class IIb; Level of Evidence B). Guidelines recommend that in the acute phase of ischemic stroke the blood pressure should be controled under 140/90 mm Hg, but there is no clear time when start to reduce the blood presure. In clinical when ischemic stroke onset weather to reduce the blood presure, when to begin the treatment is still inconclusive. In recent years, there are more literatures aboat this problem, as well as some initial evaluation systems for clinical randomized controlled trials. But the results of the evaluation are also different. Still lack updated systematic reviews to provide a more widely used evidence. This article adopts the method of Meta analysis of ischemic cerebral apoplexy and the relationship between early treatment and prognosis of research, discussion of ischemic stroke acute phase whether treatment and prognosis of research, discuss acute ischemic stroke whether trentment should be actively, in order to provide evidence for clinical treatment.This article aims to assess the relationship of reduce blood pressure in early ischemic stroke and its prognosis. A computer search domestic and international medical database of andomized controlled clinical trials which is antihypertensive therapy on the prognosis of acute ischemic stroke,according to the inclusion and exclusion criterias, we select the relevant literatures, collect relevant data, use the software Revman5.3 calculate the value of the combined effect of RR and 95% CI. We analysis the randomized controlled trials which are reduce the blood presure when ischemic stroke onset within 48 hours. Select literatures from January 1994 to December 2015, update the system review by meta-analysis.The results show that the final studies include 14 documents, 11 English literatures and 3 Chinese literatures. The total number of the cases are 9233, 4693 cases of the experimental group and 4540 cases of the control group. Meta analysis showed that blood pressure lowering in early ischemic stroke did not affect the risk of death or dependency at 3 months or longer, the results roughly equal,(RR=1.0,95%CI 0,94 to 1.07). Z test results P = 0.96.The current meta-analysis which pooled data from all relevant trials with amalgamable outcome assessment, suggested that blood pressure lowering within 2 days after ischemic stroke onset did not affect the risk of death or dependency at 3 months or longger. There is no enough evidence to demonstrate that early blood pressure reduce in stroke will improve or aggravate the outcomes. But the current domestic or foreign-related clinical trials quality are low and still need more high quality randomized controlled trials to verify.