Predictors and in-hospital outcomes of preoperative acute kidney injury in patients with type A acute aortic dissection

Background Acute kidney injury (AKI) is common after surgery for acute aortic dissection (AAD) and increases in-hospital and long-term mortality. However, few data exist on the clinical and prognostic relevance of early preoperative AKI in patients with type A AAD. We aimed to determine the incidence and predictors of preoperative AKI and the impact of AKI on in-hospital outcomes in patients with type A AAD. Methods From May 2009 to June 2014, we retrospectively enrolled 178 patients admitted to our hospital within 48 h from symptom onset and receiving open surgery for type A AAD. The patients were divided into no AKI and AKI groups and staged with AKI severity according to the KDIGO criteria before surgery. Results AKI occurred in 41 patients (23.0%). The incidence of in-hospital complications was significantly higher in patients with preoperative AKI compared to no AKI (41.5% vs. 9.5%, P < 0.001), including renal infarction (7.3% vs. 0, P = 0.012), and it increased with AKI severity (Ptrend < 0.001). Patients with AKI had higher in-hospital mortality compared with patients without AKI, although no significant difference was found (14.6% vs. 5.1%, P = 0.079). Multivariate analysis indicated that male gender, diastolic blood pressure on admission and bilateral renal artery involvement were independent predictors of preoperative AKI in patients with type A AAD. Conclusions Early AKI before surgery was common in patients with type A AAD, and was associated with increased in-hospital complications. Male gender, diastolic blood pressure on admission and bilateral renal artery involvement were major predictors for preoperative AKI.