Abstract Background Anaemia (A) and renal impairment (RI) are frequent comorbidities in heart failure (HF) and known to impact adversely on outcome. Purpose In this post-hoc analysis, we allocated HF patients from 4 studies of the Competence Network Heart Failure at baseline to subgroups according to American Heart Association/ American College of Cardiology (AHA/ACC) HF criteria and compared prevalence rates of A and RI at each HF stage and the individual and cumulative long-term impact of these comorbidities on all-cause mortality (ACM) over a 5-year follow-up (FUP) period. Methods To study A and RI prevalence, we performed a cross-sectional analysis in 3344 patients (40.6% female, 65.6±11.2 years, 7.8, 32.3, 38.5, and 21.4% in stages A, B, C1 and C2/D, respectively). FUP data were available for 2496 patients (37.4% female, 66.0±11.3 years, 8.1, 35.3, 32.9, and 23.7% in stages A, B, C1 and C2/D, respectively). A was defined as haemoglobin <13/12 g/dL in men/women and RI as estimated glomerular filtration rate <60 mL/min/1.73m2. Within each HF subgroup, participants were divided in those without these comorbidities (A-/RI-), with either A or RI (A+/RI- and A-/RI+), or with both, A and RI (A+/RI+). For survival analysis log rank tests and multivariable Cox regression models were used. Results Overall prevalence of A in the stages A, B, C1, and C2/D was 3.1, 7.6, 16.5, and 29.8% (p<0.001) and of RI 17.6, 21.3, 24.4, and 46.6% (p<0.001), respectively. In the 4 subgroups, prevalence rates of A-/RI- were 80.2, 74.3, 66.3, and 42.1%, (p<0.001). A+/RI- and A-/RI+ were present in 2.3, 4.4, 9.3, and 11.3% (p<0.001) and 16.8, 18.1, 17.2, and 28.1 (p<0.001). A+/RI+ was found in 0.8, 3.1, 7.1, and 18.5% (p<0.001). Kaplan Meier curves demonstrate the individual and cumulative prognostic impact of A and RI (Figure). Conclusions Our results demonstrate a high prevalence in particular of RI even in asymptomatic HF stages and significant individual and cumulative long-term adverse effects of A and RI across the entire HF continuum. This includes also the clinically asymptomatic HF stages. Both prevalence and the individual and cumulative negative prognostic impact increase with increasing HF severity calling for careful consideration and management of these comorbidities in the frame of holistic HF care.