Long-Term Outcomes of Acute Kidney Injury After Different Types of Cardiac Surgeries: A Population-Based Study

Background Dialysis-requiring acute kidney injury (D-AKI) is a major complication of cardiovascular surgery that results in worse prognosis. However, the incidence and impacts of D-AKI in different types of cardiac surgeries have not been fully investigated. Methods and Results Patients admitted for cardiovascular surgery between July 1, 2004, and December 31, 2013, were identified from the National Health Insurance Research Database of Taiwan. The patients were grouped into D-AKI (n=3089) and non-D-AKI (n=42 151) groups. The outcome was all-cause mortality and major adverse kidney event. The long-term outcomes were worse in the D-AKI group than the non-D-AKI group (hazard ratio [HR], 3.89; 95% CI, 3.79-3.99 for major adverse kidney event; HR, 2.89; 95% CI, 2.81-2.98 for all-cause mortality). Patients who underwent aortic surgery had higher risk for D-AKI than other types of surgeries, but they were also more likely to recover. The long-term dialysis rate for the patients who recovered from D-AKI was also lowest in those who underwent aortic surgery. Among all types of cardiac surgeries with D-AKI, patients who had heart valve surgery exhibited the greatest risks of all-cause mortality (HR, 6.04; 95% CI, 5.78-6.32). Conclusions Compared with other heart surgeries, aortic surgery resulted in a higher incidence of D-AKI but better renal recovery, better short-term outcome, and lower incidences of long-term dialysis.