Impact of Acute Kidney Injury on Early to Long-Term Outcomes in Patients Who Underwent Surgery for Type A Acute Aortic Dissection

Abstract

Acute kidney injury (AKI) is relatively common after cardiothoracic surgery for type A acute aortic dissection (TA-AAD) and increases mortality. We investigated the incidence and risk factors for AKI in patients with TA-AAD and its impact on their outcomes. The records of 375 consecutive patients who underwent surgical treatment for TA-AAD from October 2007 to March 2013 were analyzed retrospectively. We defined AKI using the Kidney Disease Improving Global Outcomes criteria, which are based on serum creatinine concentration or glomerular filtration rate. We used Kaplan-Meier methods and multivariate Cox proportional hazards regression to assess the impact of AKI on both mortality and major adverse cardiovascular and cerebrovascular events. We also examined the association between risk factors and AKI using logistic regression modeling. Postoperative AKI was observed in 165 patients (44.0%). The overall 30-day and mid- to long-term mortality was 1.6% and 8.8%, respectively. Mortality and major adverse cardiovascular and cerebrovascular events correlated significantly with the severity of AKI, and multivariate analysis showed that AKI stage 3 (the most sever stage) was an independent risk factor for mortality (hazard ratio 6.83, 95% confidence interval 2.52 to 18.52) after adjustment for important confounding factors. Extracorporeal circulation time, body mass index, perioperative peak serum C-reactive protein concentration, renal malperfusion, and perioperative sepsis were found to be risk factors for AKI. In conclusion, AKI was common in patients who underwent surgery for type A acute aortic dissection. The severity of AKI strongly influences patient outcomes, so it should be recognized promptly and treated aggressively when possible.