Prognostic Interplay Between Chronic Kidney Disease, Anemia and Diabetes in Patients Undergoing CABG

Intoduction: Chronic kidney disease (CKD) and anemia often coexist and both may accompany diabetes. All 3 are associated with worse cardiovascular outcomes. We investigated the prognostic implications of anemia and CKD on mortality among patients undergoing coronary artery-bypass grafting (CABG) surgery, and examined whether their outcome is related to the presence of diabetes.

Metirials and Methods: Retrospective analysis of 1,180 patients undergoing CABG. Long-term mortality (mean follow-up 8.6±4.2 years) was examined in relation to the presence of preoperative anemia, CKD and diabetes. Cox proportional-hazards models were used to evaluate the prognostic interplay between the 3 risk indicators.

Results and disscusion: CKD (20% of patients), anemia (25%) and diabetes (43%), were each independent risk predictors for mortality. Compared to patients with neither CKD nor anemia, the adjusted hazard ratio [HR,(95% CI)] for mortality was 1.87,(1.35-2.59) in those with CKD only, 1.75,(1.30-2.35) in those with anemia only, and 2.69,(1.91-3.78) in patients with both CKD/anemia. The pattern of association between CKD and/or anemia with mortality was similar in patients with versus without diabetes. However, in a combined model, mortality risk was higher in patients with than without diabetes in each of the risk categories: neither CKD/anemia: [1.69,(1.20-2.39) vs. 1 (reference)] , CKD only: [2.68,(1.59-4.52) vs. 2.10,(1.38-3.20)] , anemia only: [2.73,(1.83-4.07) vs. 1.94,(1.23-3.08)], and both CKD/anemia [4.44, (2.88-6.85) vs. 2.72,(1.58-4.69)].

Conclusions: In patients undergoing CABG, anemia and CKD have significant prognostic implications on long-term mortality, both individually and more so when coexisting together preoperatively. Their effect on mortality was cumulatively associated with the adverse impact of diabetes.