Heart failure and the risk of acute kidney injury in relation to ejection fraction in patients undergoing coronary artery bypass grafting - PubMed (original) (raw)

Background: We studied the association between heart failure with reduced or preserved ejection fraction (EF) and the risk of acute kidney injury (AKI) in patients undergoing coronary artery bypass surgery (CABG).

Methods: We included all patients who underwent isolated CABG in Sweden 2003 to 2013. AKI was defined according to the Kidney Disease Improving Global Outcomes definition, as an increase in postoperative serum creatinine concentration by ≥26 μmol/L or ≥50%, compared to preoperative values. Adjusted odds ratios (OR) for AKI were calculated using logistic regression for patients with and without heart failure, and among patients with heart failure, by EF categories (<30% severely reduced; 30-40% moderately reduced; ≥50% preserved).

Results: Included were 36,403 patients of whom 3914 (11%) had heart failure. In patients with heart failure, 26% developed AKI compared with 14% in patients without heart failure. After adjustment for background characteristics, including preoperative kidney function and EF, the OR for AKI was 1.12 (95% CI 1.02-1.23) in patients with heart failure compared with no heart failure. Among patients with heart failure, the adjusted OR for AKI among patients with EF <30% vs. ≥50% was 1.32 (95% CI 1.06-1.65) and for 30-49% vs. ≥50% 1.06 (95% CI 0.87-1.28), respectively.

Conclusion: Patients with heart failure who underwent CABG had an increased risk for AKI postoperatively even after adjustment for comorbidity such as EF. Among patients with heart failure, having a severely reduced EF was associated with AKI compared to patents with preserved EF.