Brain Natriuretic Peptide Concentrations After Aneurysmal Subarachnoid Hemorrhage:Influence Factors And Prognosis

Background and objectiveRuptured intracranial aneurysm is the major cause of subarachnoid hemorrhage(SAH),and Aneurismal SAH represents a serious disease that carries a high mortality and morbidity.Cerebral vasospasm(CVS)has been regarded as the major cause of high mortality and poor outcome of SAH patients.However,after decades of research,the pathophysiology of CVS is still not clear.Over the past 30 years,more and more studies focus on the effect of vascular active substances in CVS after appearing SAH.Brain natriuretic peptide(BNP)is a very potent natriuretic,diuretic and vasodilator compound.Serum BNP level was increased significantly in patients with SAH,especially in the patients with severe CVS,which could cause delayed ischemic neurological deficit(DIND).At present,there are many studies about the change and the effect on prognosis of BNP in patients with SAH.Some studies have shown that high serum BNP level may lead to poor prognosis.Some studies have found that hyponatremia caused by high BNP has association with poor prognosis.However,the mechanism of BNP is until unclear.The purpose of this study is to explore influence factor of serum BNP level and to clarify the prognostic value of high serum BNP level in SAH patients.MethodsThis retrospective analysis included clincal and follow-up data from 116 patients with intracranial aneurysm who had confirmed by cerebral angiography at the department of neurosurgery at Qilu Hospital of Shandong University from September 2014 to September 2017.Serum BNP level and serum osmolality are measured in five stages,including preoperative and postoperative 1-3d,4-6d,7-9d and 10-12d.Meanwhile,preoperative serum white blood count(WBC),neutrophils and-sodium are measured.This study explored the variation trend of serum BNP level in the development of disease,and connection between SAH Fisher grade,Hunt-hess classification,WBC,neutrophils and other inflammatory index and serum BNP level.We defined DIND as short-term prognosis,and modified Rankin Scale(mRS)as long-term prognosis,and explored the effect of BNP on prognosis in patients with SAH.The two-sided P value of less than 0.05 is considered to be statistically significant.Datas are calculated by SPSS 23.0 software(Windows;IBM Corporation,Armonk,NY,USA)?ResultsThe study recruited 116 intracranial aneurysm patients,including 38 unruptured aneurysms and 78 spontaneous SAH patients caused by ruptured aneurysms.Serum BNP level in aneurismal SAH group is significantly higher than in unruptured group.Patients with the higher level of Fisher's grade are more likely to have high serum BNP level.Serum BNP levels in DIND patients is significantly higher than patients without DIND in period of preoperative and postoperative 1-3d(preoperation,P=0.001;postoperative 1-3d,P=0.004).The same results were observed in SAH subgroup analysis.Serum BNP levels increased markedly in patients with high mRS score in stage of preoperative and postoperative 1-3d,10-12d(preoperation,P=0.001;postoperative 1-3d,P=0.002;postoperative 10-12d,P<0.001).For SAH patients,serum BNP levels of patients with high mRS score is significantly higher than patients with low score in period of preoperative and postoperative 1-3d,4-6d,10-12d(preoperation,P=0.035;postoperative1-3d,P=0.005;4-6d,P=0.035;10-12d,P=0.014).In univariate analysis of the short-term prognosis,Fisher's grade 3-4 and serum BNP level?338.84ng/ml are risk factor of DIND.In multivariable analysis,we found that serum BNP level?338.84ng/ml is an independent risk factor(Odds ratio[OR]=4.91,95%Confidence interval[CI]1.53-15.78,P=0.007).The univariate analysis of the long-term prognosis found that older than 60 years old,Hunt-hess ?-?,Fisher's grade 3-4 and serum BNP level ?338.84ng/ml are the risk factors of high mRS score,and Hunt-hess ?-? is an independent risk factor.For SAH patients,older than 60 years old and serum BNP level?338.84 ng/ml is an independent risk factor.In single-variable analysis of the long-term prognosis,there are some found that older than 60 years old,serum BNP level?338.84ng/ml,Hunt-hess III-V is are risk factors of high mRS score.Hunt-hess III-V is an independent risk factor(OR=10.04,95%CI 2.52-40.09,P=0.001).The preoperative serum sodium and every stage of serum osmolality have no statistically difference for short-or long-term outcome.Serum BNP level is positively correlated with WBC and neutrophils,and negatively correlated with lymphocytes.This may indicates that high serum BNP level after SAH is associated with stress.ConclusionThe present study shows plasma BNP levels are markedly increased in the short time in patients with SAH,especially patients with DIND and high mRS score.Meanwhile,plasma BNP level is associated with age,hemorrhage,clinical symptom and inflammatory cell number,this shows that elevated BNP may be caused by cardiogenic secretion related to stress.Plasma BNP level>338.84ng/ml was an independent predictor of DIND.