Acute Kidney Injury Following 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) following surgery for acute type A aortic dissection (ATAAD) using the NORCAAD registry.

METHODS: Patients that underwent ATAAD surgery at eight Nordic centers from 2005-2014 were analyzed for AKI according to the RIFLE-criteria. Patients who died intraoperatively, those who had missing baseline or postoperative serum creatinine (SCr), and patients on preoperative RRT, were excluded.

RESULTS: AKI occurred in 382/941 (40.6%) patients and postoperative dialysis was required for 105 (11.0%) patients. Renal malperfusion was present preoperatively in 42 (5.1%) patients, of whom 69.0% developed postoperative AKI.In multivariable analysis, patient-related predictors of AKI included age (per 10 years, OR=1.30, 95% 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=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<0.001). In 30-day survivors, AKI was an independent predictor of long-term mortality (HR=1.86, 95% CI:1.24-2.79).

CONCLUSIONS: AKI is a common complication following 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 due to 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.