Acute Kidney Injury After Acute Repair of Type A Aortic Dissection

Background: The aim of this study was to examine the incidence, risk factors, and outcomes of patients with acute kidney injury (AKI) after surgery for acute type A aortic dissection (ATAAD) using the Nordic Consortium for Acute Type A Aortic Dissection registry. Methods: Patients who underwent ATAAD surgery at 8 Nordic centers from 2005 to 2014 were analyzed for AKI according to the RIFLE criteria. Patients who died intraoperatively, those who had missing baseline or postoperative serum creatinine, and patients on preoperative renal replacement therapy were excluded. Results: AKI occurred in 382 of 941 patients (40.6%), and postoperative dialysis was required for 105 patients (11.0%). Renal malperfusion was present preoperatively in 42 patients (5.1%), of whom 69.0% developed postoperative AKI. In multivariable analysis patient-related predictors of AKI included age (per 10 years; odds ratio [OR], 1.30; 95% confidence interval [CI], 1.15-1.48), body mass index >30 kg/m² (OR, 2.16; 95% CI, 1.51-3.09), renal malperfusion (OR, 4.39; 95% CI, 2.23-9.07), and other malperfusion (OR, 2.10; 95% CI, 1.55-2.86). Perioperative predictors were cardiopulmonary bypass time (per 10 minutes; OR, 1.04; 95% CI, 1.02-1.07) and red blood cell transfusion (OR per transfused unit, 1.08; 95% CI, 1.06-1.10). Rates of 30-day mortality were 17.0% in the AKI group compared with 6.6% in the non-AKI group (P < .001). In 30-day survivors AKI was an independent predictor of long-term mortality (hazard ratio, 1.86; 95% CI; 1.24-2.79). Conclusions: AKI is a common complication after surgery for ATAAD and independently predicts adverse long-term outcome. Of note one-third of patients presenting with renal malperfusion did not develop postoperative AKI, possibly because of restoration of renal blood flow with surgical repair. Mortality risk persists beyond the perioperative period, indicating that close clinical follow-up of these patients is required.