Anemia Increases Mortality After Open or Endovascular Treatment in Patients with Critical Limb Ischemia: A Retrospective Analysis

Abstract

Pre-operative anemia has been associated with increased post-operative morbidity and mortality in elective cardiac surgery, but its association with post-operative mortality after open or endovascular surgery for critical limb ischemia (CLI) is not well established. The aim of this study was to evaluate the relationship between pre-operative anemia and mortality in surgery for CLI. A retrospective study of 403 consecutive patients (mean age = 73; 73% male) undergoing open (n = 191, 47%) or endovascular (n = 212, 53%) surgery for CLI between 2005 and 2013 was performed. Neither redo revascularization procedures (ipsilateral or contralateral) nor acute limb ischemia patients were included as new cases. The best cut off (receiver operating characteristic curve) that related pre-operative hemoglobin to mortality was 10 g/dL. The immediate (in hospital or < 30 days) mortality rate was 8% (32 patients), with no significant differences between open and endovascular surgery. Patients with a pre-operative hemoglobin <10 g/dl had a higher immediate mortality rate (17.7% vs. 5.1%), with a risk (OR), adjusted by age and prior myocardial infarction, of 3.9, 95% CI 1.8-8.4 (p = 0.001). The mean follow up of the cohort was 30 months (97% complete). Similarly, a pre-operative hemoglobin <10 g/dL was significantly associated with a lower 1 year (55 vs. 83%) and 5 year survival rate (21 vs. 53%) with an associated risk (HR) of 2.5, 95% CI 1.8-3.4 (p < 0.001) adjusted by age, previous myocardial infarction, chronic renal failure, stroke, diabetes mellitus, and ischemic ulcers. Pre-operative anemia is a risk factor for immediate and late mortality among patients with CLI, regardless of other risk factors and the type of revascularization technique. Prospective studies are needed to evaluate the potential effect of its treatment on survival outcomes.