Impact of Preoperative Anemia and Postoperative Hemoglobin Drop on the Incidence of Acute Kidney Injury and In-Hospital Mortality in Patients With Type B Acute Aortic Syndromes Undergoing Thoracic Endovascular Aortic Repair

Background: The impact of preoperative anemia and postoperative hemoglobin (Hb) drop on the incidence of acute kidney injury (AKI) after thoracic endovascular aortic repair (TEVAR) for type B acute aortic syndromes (AAS) as well as their prognostic value is unknown. Methods: This retrospective study included 144 patients with type B AAS undergoing TEVAR at our center. Preoperative anemia was classified as no/mild (Hb ≥ 12.0 g/dL in men; ≥11.3 g/dL in women), moderate (Hb 10.80-11.99 g/dL in men; 10.23-11.29 g/dL in women), and severe (<10.80 g/dL in men; <10.23 g/dL in women). Postoperative Hb drop was classified as mild (<2 g/dL), moderate (2-4 g/dL), and severe (>4 g/dL). End points of the study were postoperative AKI and in-hospital mortality. Results: Postoperative AKI was higher in the severe and moderate anemia groups than the no/mild anemia group (63.2%, 52.0%, and 31.0%, respectively, P = .01). In-hospital mortality and AKI were higher in patients with severe postoperative Hb drop (40.9% and 86.4%) than patients with moderate (6.9% and 36.2%) and mild (4.7% and 25.0%) postoperative Hb drop (both P < .001). Postoperative Hb drop (odds ratio [OR]:1.67, P = .036), postoperative Hb levels (OR: 0.57, P = .025), and mesenteric ischemia (OR: 4.65, P = .044) were identified as independent predictors of in-hospital mortality. Preoperative Hb (OR: 0.26, P = .001), postoperative Hb drop (OR: 4.34, P < .001), contrast medium (OR: 1.82, P = .004), and diabetes mellitus (OR: 3.79, P = .001) were independent predictors of AKI. At follow-up, anemia and postoperative Hb drop were not associated with increased mortality. Conclusion: Preoperative Hb and postoperative Hb drop were significant risk factors for AKI. Postoperative Hb drop and Hb levels predicted in-hospital mortality.