Impaired Renal Function And Discharged Outcome Among Patients With Acute Ischemic Stroke

AbstractObjective:1、To explore the association between admission estimated glomerular filtration rate, serum creatinine, urea and discharged outcome among patients with acute ischemic stroke.2 、 To explore the association between clustering of renal functionindices and discharged outcome among patients with acute ischemic stroke.3、To explore the posterior probability of estimated glomerular filtration rate, serum creatinine, urea and multiple indices diagnosis test for the poor outcome of ischemic stroke.Subjects and methods:Subjects: From June 1st 2009 to May 31 2013, we recruited patients diagnosed with first or recurrent ischemic stroke who were consecutively admitted in the Departments of Neurology from three hospitals(Affiliated Zhongshan Hospital of Dalian University, Xinganmeng People’s Hospital, Affiliated Hospital of Chengde Medical College) after onset of symptoms, the total sample size was 7 011.Methods: Qualified investigators collected data which including demographic characteristics, life style information, estimated glomerular filtration rate, serum creatinine, urea and some other clinical laboratory indexes. Patients were dichotomized to two groups according to the modified Rankin Scale(m RS): good outcome(m RS 0~2) or poor outcome(m RS 3~6) at discharge.Statistical analysis: Epi Data3.1 software was used to establish the database, and all data about the questionnaires were input by two individuals, and the data was checked by software.SAS 9.2 was used for the statistical analysis. ANOVA, chi-square and Kruskal-Wallis H test were used to perform difference analysis for these variables between low, normal, high group of estimated glomerular filtration rate, serum creatinine, urea. The t-test, chi-square and Wilcoxon test were used to perform difference analyses for these variables between good and poor outcome. Binary Logistic regression analysis was used to assess the associations between estimated glomerular filtration rate, serum creatinine, urea and the risk of poor outcome of ischemic stroke. Association between poor outcome and the clustering of abnormal renal function parameters were analyzed using logistic regression.Posterior probability of estimated glomerular filtration rate, serum creatinine, urea and multiple indices diagnosis test for the poor outcome of ischemic stroke were calculated.Results:1、7 011 acute ischemic stroke patients were included in this study, the mean age was 64.2±12.1 years old, among them 4390 were male(62.6%). Mean value of estimated glomerular filtration rate was 111.68±35.88 m L/min/1.73 m2. Mean value of serum creatinine was 78.09±23.25 umol/L. Mean value of urea was 5.89±2.70mmol/L. Both urea and serum creatinine were negatively correlated to estimated glomerular filtration.2、Compared with the patients in the normal group of estimated glomerular filtration rate, patients in low group tended to be older, had higher value of systolic blood pressure, diastolic blood pressure, glucose, total cholesterol, with higher rates of heart disease and atrial fibrillation. While patients in high group tended to younger, male, had higher value of systolic blood pressure, glucose, with higher rates of smoking, drinking and lower rate of cardiovascular disease, dyslipidemia. The distribution directions of demographic characteristics among low, normal, high group of serum creatinine and urea were different with that among estimated glomerular filtration rate groups, the results were basically the same.3、5364(76.5%) patients in our study had good outcome, while 1647(23.5%) patients had poor outcome at discharge. Compared with patients with good outcome, patients with poor outcome tended to be older, with longer stay in the hospital, shorter time from onset to admission, previous ischemic stroke, had higher value of systolic blood pressure, diastolic blood pressure, glucose, high-density lipoprotein cholesterol, urea and estimated glomerular filtration rate, had lower value of total cholesterol, triglyceride, low-density lipoprotein cholesterol and serum creatinine, with lower rate of smoking, drinking and higher rate of heart disease, auricular fibrillation.4、The rates of poor outcome in low, normal, high groups of estimated glomerular filtration rate were 32.8%, 20.4%, 28.0%. The rates of poor outcome in low, normal, high groups of serum creatinine were 40.4%, 22.6% and 34.1%. The rates of poor outcome in low, normal, high groups of urea were 26.5%, 21.6% and 29.7%. Regardless of the renal function parameters, the rates of poor outcome in low and high groups were all higher than that in normal groups, while there were no differences between low and high groups.5、In the binary logistic regression analysis, after adjusting confounding factors, the ORs(95%CIs) of poor outcome were significant higher in both low and high value groups of estimated glomerular filtration rate(1.47, 1.10 ~ 1.96; 1.60, 1.41 ~ 1.82), serum creatinine(2.05, 1.55~2.71; 1.44, 1.03~2.01) and urea(1.34, 1.01~1.77; 1.39, 1.21~1.60)when compared with the normal group respectively.6、The risk of incidence of poor outcome was increased with the degree of clustering of abnormal renal function indices. After adjusting confounding factors, the OR(95%CI) of poor outcome was highest in 3 abnormal indices group which was 2.66(1.94~3.64).7、According to the China national stroke registry study, the incidence of poor outcome at discharge among ischemic stroke patients was 32.5%, thus the calculated posterior probabilities of diagnostic tests by using estimated glomerular filtration rate, serum creatinine, urea for poor outcome were 38.3%, 48.7%, 39.2%. The posterior probability of combined diagnostic test for poor outcome was 52.4%. That is, if ischemic stroke patients simultaneously had abnormal urea, serum creatinine and e GFR at admission, the possibility of poor outcome at discharge would increase by 19.9%.Conclusion:1、Both low and high estimated glomerular filtration rate, serum creatinine and urea are associated with higher risk of poor outcome at discharge among ischemic stroke patients.2、The risk of poor outcome increased with clustering of abnormal renal function indices. Combined diagnostic test of estimated glomerular filtration rate, serum creatinine and urea had the highest posterior probability.