Acute kidney injury following surgical aortic valve replacement

Acute kidney injury (AKI) is a significant complication of surgical aortic valve replacement (SAVR). This study sought to describe AKI following SAVR, its risk factors, predictors and effect on long-term survival.

We retrospectively reviewed 2169 patients who underwent isolated SAVR between 2000 and 2012. The main end-points were occurrence of AKI, postoperative complications, and short- and long-term survival rates following SAVR. Patients were divided into two groups: AKI+ (n = 181) and AKI- (n = 1945).

AKI occurred in 8.5% of patients, of which 3.9% (n = 7) needed dialysis. Predictors of AKI after SAVR were body mass index (BMI) and intraoperative packed red blood cells (PRBC) transfusion. AKI+ patients had a more complicated postoperative course and higher cumulative mortality (25% vs. 17%, p = 0.012) with a median follow-up of 4.1 years. AKI was not found to be an independent predictor of mortality.

Predictors of AKI after SAVR are increased BMI and intraoperative PRBC transfusion. AKI conferred an increase in hospital length of stay and cumulative mortality while the need for postoperative dialysis was associated with the most complicated hospital stays and the highest in-hospital and cumulative mortalities; therefore careful recognition of patients at risk of AKI is warranted for a better preoperative renal optimization. However, incidence of AKI was lower than what is reported after both on-CPB cardiac surgeries and transcatheter aortic valve replacement, moreover AKI was not found to be an independent predictor of mortality.