The impact of acute kidney injury on fatality of ischemic stroke from a hospital-based population in Joinville, Brazil

Abstract Introduction: The occurrence of acute kidney injury (AKI) after ischemic stroke has been associated to a worse prognosis. There is a lack of Brazilian studies evaluating this issue. This study aimed to describe the impact of AKI after a first-ever ischemic stroke in relation to fatality rate in 30 days. Methods: This was a retrospective hospital-based cohort. We included patients who had their first ischemic stroke between January to December 2015. AKI was defined by an increase of serum creatinine in relation to baseline value at admission ≥ 0.3 mg/dL or a rise in serum creatinine level by 1.5 times the baseline value at any point in the first week after admission. We performed a univariate and multivariate analysis to evaluate the presence of AKI with fatality in 30 days. Results: The final study population (n=214) had mean age of 66.46 ± 13.73 years, 48.1% were men, the mean NIHSS was 6.33 ± 6.27 and 20 (9.3%) presented AKI. Patients with AKI were older, had a higher score on the NIHSS, and had higher creatinine values on hospital discharge. The 30-day mortality was higher in the AKI subgroup compared to non-AKI (35% vs. 6.2%, p < 0.001). AKI was an independent predictor of fatality after an ischemic stroke but limited by severity of stroke (NIHSS). Conclusion: The presence of AKI is an important complication after ischemic stroke. Despite its impact on 30-day fatality, the predictive strength of AKI was limited by the severity of stroke.