Understanding non-prescription of guideline-directed medical therapy in acute heart failure and advanced kidney disease: a nation-wide study
S Olafsdottir, S Snaedal, H Einarsson, I Gunnthorsdottir, J Vishram-Nielsen, I J IngimarsdottirAbstract
Background
Heart failure (HF) and chronic kidney disease (CKD) frequently coexist and are associated with adverse outcomes. Patients with advanced CKD (eGFR <30 mL/min/1.73 m²) have largely been excluded from landmark HF trials, resulting in limited evidence for guideline-directed medical therapy (GDMT) and uncertainty in clinical practice.
Purpose
To describe the prevalence and clinical characteristics of CKD among patients hospitalised with acute heart failure (AHF), and to evaluate GDMT prescription, dosing, and reasons for non-prescription across renal function, with a focus on patients with LVEF ≤50% and advanced CKD, including longitudinal treatment patterns.
Methods
This retrospective nationwide observational study included patients admitted with AHF to the only tertiary cardiology centre in Iceland between 2020 and 2024, using data from the Icelandic Heart Failure Registry. Patients were included regardless of baseline renal function and stratified by CKD stage according to KDIGO criteria. GDMT prescription rates, target dose achievement, and reasons for non-prescription were assessed at discharge. Longitudinal GDMT use and dosing trajectories were analysed up to six months post-discharge.
Results
Among 2,441 patients (median age 77 years), 70.6% had LVEF ≤50% and 16.2% had CKD stages 4–5. Worsening CKD was associated with greater comorbidity and significantly lower GDMT use. In patients with LVEF ≤50%, GDMT prescription declined markedly from CKD stages 1–2 to 4–5 (RAAS-I 78% to 27%, MRA 54% to 10%, SGLT2i 51% to 20%), while beta-blockers were relatively preserved (91% to 76%). Target dose achievement was uniformly low, and kidney disease was the main documented reason for non-prescription. Patients with advanced CKD had high in-hospital (15.3%) and six-month mortality (37.2%); 30.6% were readmitted. Dose up-titration was uncommon, with no observed up-titration beyond three months post-discharge. Use of SGLT2 inhibitors at discharge increased substantially from 2.9% in 2020 to 41% in 2024.
Conclusions
In this nationwide real-world AHF cohort, CKD was common and associated with underuse and underdosing of GDMT, particularly in advanced CKD. Kidney disease, rather than haemodynamic intolerance, was the main documented barrier to treatment. Despite high mortality and morbidity, GDMT optimisation and post-discharge up-titration were minimal. These findings highlight a major treatment gap and the need for stronger evidence and implementation strategies to optimise GDMT in patients with HF and severe renal dysfunction.Figure 1For image description, please refer to the figure legend and surrounding text.