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

Ida Löfman, Karolina Szummer, Ulf Dahlström, Tomas Jernberg, Lars H. Lund

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. 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 m(2) . 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)]. 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.