Abstract 3425: Anemia Is Associated With Abdominal Aortic Aneurysm (AAA) Size And Decreased Long-term Survival After Endovascular Aaa Repair
Objective: Anemia is a common co-morbid condition in various inflammatory states and an established predictor of mortality in patients with chronic heart failure, ischemic heart disease and end-stage renal disease. The present study of patients with abdominal aortic aneurysm (AAA) undergoing endovascular repair (EVAR) assessed the relationships between baseline hemoglobin concentration and AAA size, as well as anemia and long-term survival.
Methods: Between 03/1994 and 11/2006, 711 patients (65 women, mean age 75.8 ± 7.8 years) underwent elective EVAR. Anemia was defined as a hemoglobin level <13 g/dL in men and <12 g/dL in women. Post-EVAR mean follow-up was 48.3 ± 32.0 months. Association of hemoglobin level with AAA size was assessed with multiple linear regression. Mortality was determined with use of the internet-based Social Security Death Index and the electronic hospital record. Kaplan-Meier survival curves of anemic and non-anemic patient groups were compared by the log-rank method. Multivariable logistic regression models were used to determine the influence of anemia on vital status after EVAR.
Results: 218/711 (30.7%) of AAA patients undergoing EVAR had anemia at baseline. After adjustment for various risk factors, hemoglobin level was inversely related to maximum AAA diameter (β: −.144, 95%-CI: −1.482- − .322, P= .002). Post-EVAR survival was 65.5% at 5 years and 44.4% at 10 years. In long-term follow-up, survival was significantly lower in patients with anemia as compared to patients without anemia (P< .0001 by log-rank). Baseline hemoglobin levels were independently related to long-term mortality in multivariable Cox regression analysis adjusted for various risk factors (adjusted HR: 0.866, 95%-CI: .783 – .958, P= .005). Within this model, statin use (adjusted HR: .517, 95%-CI: .308 – .868, P= .013) was independently related to long-term survival, whereas baseline AAA diameter (adjusted HR: 1.022, 95%-CI: 1.009 –1.036, P= .001) was an independent predictor of mortality.
Conclusions: Baseline hemoglobin concentration is an independent predictor of AAA size and reduced long-term survival following EVAR. Thus, the presence or absence of anemia offers a potential refinement of existing risk stratification instruments.