The impact of acute kidney injury on in-hospital mortality in acute ischemic stroke patients undergoing intravenous thrombolysis

Introduction Acute kidney injury (AKI) increases the risk of death in acute ischemic stroke (AIS) patients. Intravenous thrombolytic therapy (iv. rt-PA) seems to be the most effective treatment for AIS patients. The effects of AKI on iv. rt-PA treated AIS cases is less studied. Our paper addresses this issue. Methods 45 consecutive stroke patients treated with iv. rt-PA (median age = 64 years; 29 male) and 59 age and sex matched controls not eligible for iv. rt-PA have been enrolled in our study. Subjects were followed-up until hospital release or death (median follow up time = 12 days). Results The prevalence of AKI did not differ between iv. rt-PA treated patients and controls (35.5% vs. 33.89%). In both groups, AKI was associated with increased in-hospital mortality: 50.0% vs. 3.4% p<0.0001 (in the rt-PA treated), and 45% vs. 30.7% (in controls). AKI iv. rt-PA treated patients had a significantly higher risk of in hospital mortality as compared to the no-AKI iv. rt-PA treated (HR = 15.2 (95%CI [1.87 to 124.24]; P = 0.011). In a Cox-multivariate model, the presence of AKI after iv. rt-PA remained a significant factor (HR = 8.354; p = 0.041) influencing the in-hospital mortality even after correction for other confounding factors. The independent predictors for AKI were: decreased eGFR baseline and elevated serum levels of uric acid at admission, (the model explained 60.2% of the AKI development). Conclusions The risk of AKI was increased in AIS patients. Thrombolysis itself did not increase the risk of AKI. In the iv. rt-PA patients, as compared to non-AKI, those which developed AKI had a higher rate of in-hospital mortality. The baseline eGFR and the serum uric acid at admission were independent predictors for AKI development in the iv. rt-PA treated AIS patients.