Association Between Blood Pressure Variability And Short-Term Outcome In Patients With Acute Spontaneous Subarachnoid Hemorrhage

Background and objective: The association between the blood pressure variability(BPV)and the clinical outcome of patients with acute spontaneous subarachnoid hemorrhage(SAH)remains unclear.The aim of this study was to investigate the relationship between the BPV within the first 24 hours after admission and the short-term outcome of patients with acute spontaneous SAH.Materials and Methods: We retrospectively identified patients with acute spontaneous SAH admitted to Department of Neurology at the First Affiliated Hospital of Guangxi Medical University from January 2015 to May 2018.Blood pressure values were recorded at admission and subsequently at an interval of 2hours during the initial 24 hours of hospitalization.BPV was determined as difference between maximum and minimum(max-min),standard deviation(SD),co-efficient of variation(CV),and successive variation(SV).Glasgow ComaScale(GCS)and Barthel Index(BI)were performed on the admission and discharge of the patients,and the percentage of neurological changes(GCS%,BI%)was calculated based on the scores.The functional outcome at discharge was assessed according to the Glasgow Outcome Scale(GOS)and modified Rankin Scale(mRS).According to the mRS score,patients were divided into functional independence group(mRS,0-2),moderate and above disability group(mRS,3-5 points),and death group(mRS,6).We further categorized the outcomes as favorable(GOS,4-5)versus unfavorable(GOS,1-3)according to the GOS score.The statistical analysis was performed on the obtained data.Results: A total of 303 patients(155 males and 148 females)with SAH were enrolled.The average age of these 303 patients was 57.04±12.53 years old.When the clinical characteristics of the favorable group were compared with those of the unfavorable group,patients with poor outcomes were older,with a more frequent history of hypertension,excessive drinking,and aneurysm,with higher body mass index and BPV,and with worse neurological status at admission(p<0.05);The group with greater systolic BPV group had a higher incidence of rebleeding when compared with the group with lower systolic BPV.In the groups divided by mRS score,the higher the degree of dysfunction,the greater the BPV,and the greatest BPV in the death group(p<0.05);The BPV parameters were categorized into tertiles and were then entered into multivariable analysis models after adjusting the effects of variable confounders.The systolic BPV parameters were associated in a graded fashion with pooroutcomes,the greater the systolic BPV,the higher the risk of poor outcome at discharge.Whereas,the diastolic BP was not associated with prognostic risk(P>0.05);In spearman correlation analysis found that the BPV of systolic BP was negatively correlated with the percentage of neurological changes(GCS%,BI%),while the BPV of diastolic BP was no correlation.Conclusion: Age,hypertension,excessive drinking,body mass index,with cerebral aneurysm,neurological status at admission,and BPV were the prognostic factor for short-term outcome(2 weeks)of patients with acute SAH.Systolic BPV affected the occurrence of acute rebleeding in SAH patients.The higher the degree of dysfunction in SAH patients,the higher the BPV,and the highest BPV was showed in the death group.And the greater the systolic BPV within the first 24 hours after admission in patients with acute SAH,the higher the risk of poor short-term(2 weeks)outcome.