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.