The Impact of Acute Kidney Injury on the Long-term Risk of Stroke

Background-The incidence of acute kidney injury (AKI) requiring dialysis in hospitalized patients is increasing; however, information on the long-term incidence of stroke in patients surviving to discharge after recovering from AKI after dialysis has not been reported. Methods and Results-Patients that survived after recovery from dialysis-requiring AKI during index hospitalizations from 1999 to 2008 were identified in nationwide administrative registries. The risk of de novo stroke and death were analyzed with time-varying Cox proportional hazard models. The results were validated by a critical care database. We enrolled 4315 patients in the AKI-recovery group (men, 57.7%; mean age, 62.8+/-16.8 years) and matched 4315 control subjects as the non-AKI group by propensity scores. After a median follow-up period of 3.36 years, the incident stroke rate was 15.6 per 1000 person-years. The AKI-recovery group had higher risk (hazard ratio: 1.25; P=0.037) and higher severity of stroke events than the non-AKI group, regardless of progression to subsequent chronic kidney disease. The rate of incident stroke was not statistically different in those with diabetes alone (without AKI) and in those with AKI alone (without diabetes) after hospital discharge (P=0.086). Furthermore, the risk of mortality in the AKI-recovery group was higher than in the non-AKI group (hazard ratio: 2.4; P<0.001). Conclusions-The patients who recovered from AKI had a higher incidence of developing incident stroke and mortality than the patients without AKI, and the impact was similar to diabetes. Our results suggest that a public health initiative is needed to enhance postdischarge follow-up of renal function and to control the subsequent incidence of stroke among patients who recover from AKI after dialysis.