Acute kidney injury without need for dialysis, incidence, its impact on long-term stroke survival and progression to chronic kidney disease

INTRODUCTION: Patients who had a stroke are at increased risk of sepsis, dehydration and fluctuations in blood pressure, which may result in acute kidney injury (AKI). The impact of AKI on long-term stroke survival has not been studied well. OBJECTIVE: We aimed to identify incidence of AKI during acute stroke, follow-up period and its impact on long-term survival and development of chronic kidney disease (CKD). DESIGN, SETTING AND PARTICIPANTS: Retrospective analysis of patients who had a stroke admitted at the rehabilitation facility in Changi General Hospital, Singapore, between June 2008 and May 2017, with median follow-up of 141 (95% CI 120 to 163) months. OUTCOME MEASURES AND RESULTS OF UNIVARIATE ANALYSIS: Total 681 patients, median age (63.6) years, 173 (28%) died during follow-up. Elevated blood urea (3.02, 95% CI 2.17 to 4.22; p≤0.001) and creatinine (1.96, 95% CI 1.50 to 2.57; p≤0.001) during stroke affected survival adversely. Excluding patients with CKD, we analysed the remaining 617 patients. AKI was noted in 75 (12.15%) patients during the index admission, and it affected survival adversely (2.16, 95% CI 1.49 to 3.13; p<0.001). Of the patients with AKI, 21 of 75 (28%) progressed to CKD over a median follow-up of 40.7 months. CONCLUSIONS: We found AKI during stroke admission was associated with increased mortality as compared with those without AKI on univariate analysis. AKI without need of renal replacement therapy was also associated with progression to CKD in this cohort. This suggests that patients with AKI need to have their renal function monitored longitudinally for development of CKD.