High Uric Acid Is Independently Associated With Long Term Outcome Of Thrombolysed Stroke Patients

Background and Objective: Intravenous thrombolysis is considered to be one of the most effective treatments for acute ischemic stroke within 4.5 hours.Oxidative stress is one of the most important pathogenesis of acute ischemic stroke.As the most abundant endogenous antioxidant in blood,the neuroprotective effect of uric acid(UA)has been concerned.Several studies have explored the relationship between uric acid levels and short-term and long-term prognosis of acute ischemic stroke,but there have different results.Related studies suggest exogenous UA and alteplase exert additive neuroprotective effects when administered in combination,and higher UA levels at stroke admission are associated with a better outcome.However,whether the neuroprotective effect of uric acid is independent or incidental is still controversial.This study was designed to evaluate the relationship of uric acid levels to long term outcome of ischemic stroke patients treated with rt-PA.Methods: Consecutive antierior circulation AIS patients who received intravenous rt-PA within 4.5 hours of symptom onset between January 2014 and March 2017 were enrolled in this study.According to the inclusion/exclusion criteria,403 patients were included in the study.Demographic data,and clinical data such as treatment drugs,laboratory examination,brain and neurovascular imaging,TOAST classification,NIHSS were recorded.According to the level of serum uric acid,patients were divided into 3 groups.The modified Rankin Scale score(mRS)at 90 days after thrombolysis was used as an index for evaluating neurological function.The mRS score of 0-1 was defined as a good prognosis,and the mRS score of 2-6 was defined as a poor prognosis.Demographic data,basic and clinical data were compared between two groups by univariate and multivariate statistical analysis(SPSS 20.0 software).Multiplicative interaction was performed to text whether interaction existed between UA and other variables which might be correlated with clinical outcomes.Results: A total of 403 participants were included in the study,and 287(71.2%)were male.There were statistical differences in male gender{76(56.3%),107(75.4%),104(82.5%),P<0.001},diabetes history {44(32.6%),25(17.6%),28(22.2%),P=0.012},AF history {15(11.1%),23(16.2%),23(16.2%),P=0.001},Cr(61.0+13.0,68.2+13.6,86.5+44.4,P<0.001),BUN(5.4+1.4,5.7+4.9,6.3+2.7,P=0.090),GLU(8.2+3.7,7.1+2.6,7.8+3.8,P=0.020)and fibrinogen among the 3 groups of low,medium,and high levels of uric acid.11 patients occurred sICH in three groups{4(3.0 %),4(2.8%),3(2.4%),P=0.057},and there were no significant differences.At3-month,236 patients(54%)had a good outcome by mRS 0-1,167 patients(46%)had a poor outcome by mRS 2-6.In the univariate analysis,age,male gender,CHD history,AF history,baseline NIHSS,UA,BUN,Hcy,GLU,hsCRP,D-Dimer levels and TOAST classification were showed statistically significant between the two groups(P < 0.05).In the multivariate logistic regression analysis,the results suggested that high levels of UA(OR 0.850,95% CI 0.804-0.898,P<0.001),low baseline NIHSS(OR 0.850,95%CI 0.804-0.898,P<0.001),low Hcy(OR 0.960,95% 0.932-0.989,P=0.007),low GLU(OR 0.890,95% 0.812-0.976,P=0.013)and small vessel occlusion of stroke subtype might be associated with excellent outcomes(P<0.05).Furthermore,no multiplicative interaction was found between UA and other factors such as baseline NIHSS,Hcy,GLU and TOAST classification(P >0.05)in the multiplicative interaction analysis.Conclusions: Single-center experience suggests that high levels of UA might be an independent protective factor of long term functional outcomes for ischemic stroke patients treated with intravenous rt-PA.