Impact of acute kidney injury on one-year survival after surgery for aortic dissection

Background: Surgical treatment is an option for both type A aortic dissection and complicated type B aortic dissection. Acute kidney injury (AKI) influences the disease course after surgery. Our hypothesis was that AKI should be an important prognostic factor for aortic dissection after surgical treatment.

Methods: Between July 2005 and October 2010, 268 patients (mean age 53 ± 14 years; range, 16 to 88) underwent open surgery for aortic dissection. We reviewed the clinical presentations, surgical variables, and postoperative outcomes to identify the risk factors of death. The 256 patients were divided into groups, with and without AKI, within 24 hours after operation according to the RIFLE (acronym for risk, injury, failure, loss, end stage) criteria.

Results: The in-hospital mortality rate was 17.9%, the 1-year mortality rate was 18.7%, and the major adverse cardiac events rate within 1 year was 29.9%. In multivariate analysis, patients more than 70 years of age (hazard ratio [HR] 2.390, p = 0.029), cardiogenic shock (HR 2.895, p = 0.005), preoperative ventilator use (HR 4.137, p = 0.018), operation at midnight (HR 2.295, p = 0.028), longer bypass time (HR 1.007, p < 0.001), and AKI (HR 2.552, p = 0.041) were clinical predictors of mortality. Kaplan-Meier analysis showed that the survival rate was strongly correlated with the severity of AKI by the RIFLE criteria. The independent predictors of AKI included hypertension (odds ratio 2.340, p = 0.027), sepsis (odds ratio 2.594, p = 0.043), and lower limb malperfusion (odds ratio 4.558, p = 0.022).

Conclusions: Our study provides outcomes of postoperative aortic dissection. We found that AKI was a predictor of 1-year mortality by using the RIFLE criteria. Factors associated with increased 1-year mortality and AKI should be taken into consideration for surgery and postoperative care.