The Association Between Serum Sodium Level And Clinical Outcomes After Intravenous Thrombolysis In Patients With Acute Ischemic Stroke

Background and Objective:Hyponatremia is the most common electrolyte disorder encountered in patients with neurological conditions,such as stroke.Studies have shown that it is associated with worse clinical outcomes and increased mortality in acute ischemic stroke(AIS).However,the role of hyponatremia has not been elucidated in patients with AIS who received intravenous thrombolysis(IVT)therapy.Therefore,this study aimed to investigate the effect of serum sodium levels on the clinical outcome and hemorrhagic transformation(HT)in patients with AIS who received thrombolytic therapy.Materials and Methods:Patients diagnosed with AIS who received IVT therapy between May 2015 and December 2020 were included in this study.All patients were screened for serum sodium levels immediately after hospital admission,before IVT therapy.The occurrence of HT was evaluated using computed tomography(CT)24 +/-2 h after thrombolysis.Then,3-month clinical outcomes and 6-month death were obtained by telephone calls or outpatient visits.Poor 3-month clinical outcomes were defined as modified Rankin Scale scores ≥ 3.Hyponatremia was defined as serum sodium level<135 mmol/L.The effects of serum sodium levels on the clinical outcome and HT were assessed using the multivariate logistic regression analysis.Results:Of the 963 included patients,82(8.5%)had hyponatremia,157(16.3%)developed HT,333(34.6%)had poor 3-month outcomes and 98(10.2%)had 6-month death.Of the 82 patients with hyponatremia,21(25.6%)developed HT,39(47.6%)had poor 3-month outcomes and 16(19.5%)had 6-month death.Patients with hyponatremia had a higher incidence of post-thrombolysis HT(25.6 vs.15.4%,p=0.017),worse clinical outcome(47.6 vs.33.4%,p=0.01)and higher 6-month death incidence(19.5% vs.9.3%,p=0.003)than those with normal serum sodium levels.Patients had significantly lower serum sodium levels in those with HT [138.4(136.4-140.3,IQR)vs.139.0(137.2-140.7,IQR)mmol/L,p=0.019],poor 3 month outcome [139.0(137.2-140.7,IQR)vs.138.4(136.7-140.3,IQR)mmol/L,p=0.005] and higher 6-month death incidence[138.1(135.0-141.2,IQR)vs.138.8(135.8-141.8,IQR)mmol/L,p=0.004] than those without.After adjusting for major covariates,the multivariate logistic regression analysis revealed that hyponatremia was independently associated with an increased risk of HT [odds ratio(OR)=1.804;95% CI: 1.048–3.105;P=0.033],poor 3-month outcome(OR=1.647;95% CI: 1.012-2.679;P=0.045)and higher 6-month death incidence(OR=0.893;95% CI: 0.827-0.963;P=0.004).As the serum sodium level decrease,the incidence of HT(OR=0.939;95% CI: 0.894-0.996;P=0.037),poor 3-month outcome(OR=0.938;95% CI: 0.886-0.984;P=0.009)and 6-month death(OR=0.893;95% CI: 0.827-0.963;P=0.003)become higher.Conclusions:For patients with AIS who received IVT,hyponatremia before thrombolysis was an independent risk factor for post-thrombolysis HT,poor 3-month outcome and higher6-month death mortality.As the serum sodium level decrease,the incidence of HT,poor3-month outcome and 6-month death become higher.