Associations with and prognostic impact of chronic kidney disease in heart failure with preserved, mid-range, and reduced ejection fraction.

AIMS: As the role of chronic kidney disease (CKD) in different types of heart failure (HF) is poorly understood, our aim was to compare CKD in HF with preserved (HFpEF), mid-range (HFmrEF), and reduced ejection fraction (HFrEF) with regard to prevalence, associations and prognostic role.

METHODS AND RESULTS: Patients in the Swedish Heart Failure Registry were divided into three groups based on EF (≥50%, 40-49% and <40%). CKD was defined as an estimated glomerular filtration rate ≤60 mL/min.1.73 m2 . Associations between covariates and CKD and between CKD and mortality were assessed with multivariable regressions. Of 40 230 patients, 8875 (22%) had HFpEF, 8374 (21%) had HFmrEF, and 22 981 (57%) had HFrEF, with a CKD prevalence of 56%, 48%, and 45%, respectively. Associations between covariates and CKD were similar in all EF groups. One-year mortality with vs. without CKD was 23% vs. 13% in HFpEF, 22% vs. 8% in HFmrEF, and 23% vs. 8% in HFrEF (P < 0.001 for all). After adjustment, CKD was more strongly associated with death in HFrEF and HFmrEF than in HFpEF [hazard ratio (HR) and 95% confidence interval (CI); 1.49 (1.42-1.56) and 1.51 (1.40-1.63) vs. 1.32 (1.24-1.42); P for interaction <0.001]. In receiver operating characteristic (ROC) analyses, CKD was also a stronger predictor of death in HFrEF and HFmrEF than in HFpEF [area under the curve (AUC) 0.699 (0.689-0.709) and 0.700 (0.683-0.716) vs. 0.629 (0.613-0.645)].

CONCLUSION: CKD was associated with similar covariates regardless of EF. Although CKD was more common in HFpEF than in HFmrEF and HFrEF, it may have more of a 'bystander' role in HFpEF, being less associated with mortality and with lower prognostic discrimination.