Risk factors and long-term outcomes of acute kidney injury complication after type A acute aortic dissection surgery in young patients

OBJECTIVE: To identify risk factors and long-term outcomes of acute kidney injury (AKI) in young patients who underwent type A acute aortic dissection (TA-AAD) emergency surgeries. METHODS: This retrospective study enrolled 121 consecutive patients less than 40 years old who received TA-AAD emergency surgeries between January 2014 to December 2018 in Nanjing Drum Tower hospital. The diagnosis of AKI was made based on the KDIGO criteria. Multivariable regression analysis was performed to identify risk factors for postoperative AKI. Kaplan–Meier curves were generated to compare long-term outcomes between patients with and without AKI complication after TA-AAD surgeries. RESULTS: Among all enrolled patients, AKI occurred in 51 patients (42.1%) and renal replacement therapy (RRT) was required in 15 patients (12.4%). The development of postoperative AKI was associated with increased 30-day mortality (P = 0.041), longer ICU stay time (P < 0.001) and hospital stay time (P = 0.006). Multivariable analysis indicated that elevated preoperative serum cystatin C (sCyC) (OR = 6.506, 95% CI: 1.852–22.855, P = 0.003) was the only independent risk factor for developing AKI. The areas under the receiver-operating characteristic curve (AUC) of preoperative sCyC was 0.800 (95% CI: 0.719, 0.882). Preoperative sCyC had a sensitivity of 64.7% and a specificity of 83.8% in diagnosing postoperative AKI with a cut-off value of 0.895 mg/L. In addition, our data suggested there was no difference discovered regarding long-term cumulative survival rate between patients with and without AKI during a median 29 months follow-up period. CONCLUSIONS: Postoperative AKI after TA-AAD surgeries was relatively common in young patients and associated with increased short-term mortality. Elevated preoperative sCyC was identified as an independent risk factor for AKI with potential diagnostic merit.