Prognostic Interplay of Chronic Kidney Disease, Anemia, and Diabetes in Coronary Bypass Surgery

Abstract

Background: Chronic kidney disease and anemia often coexist and may accompany diabetes; all 3 conditions are associated with worse cardiovascular outcomes. This study investigated the prognostic implications of anemia and chronic kidney disease for mortality among patients undergoing coronary artery-bypass grafting surgery and examined whether outcomes are related to the presence of diabetes.

Methods: This retrospective study included 1180 patients undergoing coronary artery-bypass grafting. Long-term mortality (mean follow-up, 8.6 ± 4.2 years) was examined in relation to preoperative anemia, chronic kidney disease, and diabetes. Prognostic interplay of the 3 risk factors was evaluated.

Results: Chronic kidney disease, anemia, and diabetes (20%, 25%, and 43% of patients, respectively), were independent risk predictors for mortality. Compared with patients with neither chronic kidney disease nor anemia, the adjusted hazard ratios (HRs) for mortality were 1.87 (95% confidence interval [CI], 1.35 to 2.59) in chronic kidney disease only, 1.75 (95% CI, 1.30 to 2.35) in anemia only, and 2.69 (95% CI, 1.91 to 3.78) in patients with both conditions. The pattern of association of chronic kidney disease and anemia with mortality was similar in patients with and without diabetes. However, mortality risk was higher in patients with diabetes in each risk category-neither chronic kidney disease nor anemia: HR, 1.69 (95% CI, 1.20 to 2.39) vs HR, 1 (reference); chronic kidney disease only: HR, 2.68 (95% CI, 1.59 to 4.52) vs HR, 2.10 (95% CI, 1.38 to 3.20); anemia only: HR, 2.73 (95% CI, 1.83 to 4.07) vs HR, 1.94 (95% CI, 1.23 to 3.08); and both chronic kidney disease and anemia: HR, 4.44 (95% CI, 2.88 to 6.85) vs HR, 2.72 (95% CI, 1.58 to 4.69).

Conclusions: In patients undergoing coronary artery-bypass grafting, anemia and chronic kidney disease have significant prognostic implications for long-term mortality. Their effect on mortality was cumulatively associated with adverse impacts of diabetes.