Is Preoperative Eosinopenia an Independent Predictor of Early Mortality for Coronary Artery Bypass Surgery?

Coronary artery bypass graft surgery in one of the most effective and widely used methods employed in the treatment of ischemic heart disease, but many factors to various degrees are directly associated with perioperative and postoperative problems. In this study, we evaluated the relationship between preoperative eosinophil count and postoperative mortality in patients who underwent coronary artery bypass graft operation.

A total of 241 patients (157 males, 84 females) who underwent isolated on-pump coronary artery bypass graft operation between 2011 and 2013 in two centers were evaluated retrospectively. The mean age of patients was 64 ± 11 years. After the mean 6.2 ± 0.8 month follow-up period, 36 (15%) of the 241 patients experienced cardiovascular death. Patients were classified into two groups as those who survived versus those who died.

Eosinophil levels were lower among the patients who died compared to the patients who survived (0.8 [0-3.8] versus 1.7 [0-9.4] ×1000 cells/mm3; P < .001). Optimal cut-off level of eosinophils for predicting mortality was determined as ≤1.6 ×1000 cells/mm3, with a sensitivity of 85.7% and specificity of 51.0% (area under curve, 0.703; 95% CI, 0.641-0.760).

Eosinopenia was used as the predictor of mortality in pediatric and adult patients in the intensive care units. Eosinopenia after coronary artery bypass graft can be related to the endogenous stress hormones, and insufficiency of the existing cardiac status. Eosinophil levels can assist and facilitate risk stratification for patients with coronary artery bypass graft.