#2970 Heart failure with preserved ejection fraction on chronic kidney patients: innocent bystander? A cohort study in Portuguese population
Authors: Almeida Ana Rita , Santos Filipe Mafalda Dias de Carvalho e , Falcao Luis , Donato Beatriz , Fernandes Adriana , Silva Sónia 
Published: May 2024

Abstract

Background and Aims
Heart failure (HF) consists in a significant public health challenge, with high prevalence worldwide and a substantial impact on morbidity and mortality. In chronic kidney disease (CKD), HF can act both as a risk factor and a complication, exacerbating the overall outcomes for affected individuals. This study aims to elucidate the prevalence of distinct types of heart failure, encompassing preserved ejection fraction (HFpEF), mid-range ejection fraction (HFmrEF), and reduced ejection fraction (HFrEF) in CKD patients. Moreover, we purpose to identify the potential of these subtypes to influence the outcomes of mortality and start of kidney replacement therapy (KRT), as a different therapeutic approach is suitable for each.

Method
Observational retrospective cohort study of 3008 CKD patients, with follow-up in Nephrology out-patient clinic in a Portuguese hospital, from February, 2012 to October, 2019. Ejection fraction was accessed by echocardiogram and information was collected from health records. To access mortality, patients who started KRT along the study were excluded.

Results
A total of 3008 patients, of which 91.7% Caucasians and 54.5% males, with an average age of 68.2 (±15.9) years was enrolled in the study. The mean follow-up time was 3.21 (±1.97) years and the mean estimated glomerular filtration rate at baseline was 47.63 ± 33.1 ml/min/1.73 m2. Among the participants, 769 individuals (25.5%) were diagnosed with HF. Specifically, 319 patients (41.5%) exhibited HFpEF; 85 patients (11%) had HFmrEF, and 117 patients (15.2%) had HFrEF, while the ejection fraction (EF) was unknown in 32.2% of cases. In the HF group, the incidence of diabetes was 55.6%, compared to 37.5% in the non-HF group. As for hypertension, the prevalence of was 91.8% in the HF group and 78.6% in the non-HF group. When assessing all-cause mortality during the follow-up, the hazard ratio (HR) for the HF group was 3.54 (95% CI, 2.94-4.26) compared to the non-HF group. Furthermore, for the initiation of KRT, the HR was 1.57 (95% CI, 1.19-2.06), favoring patients without heart failure. Across different types of HF, in comparison to the group without HF, the hazard ratio during follow up were notably different. Specifically, the HR was 5.39 (95% CI, 3.66-7.94) for patients with HFrEF, 3.43 (95% CI, 2.18-5.40) for patients with HFmrEF and 2.99 (95% CI, 2.32-3.87) for the HFpEF. When assessing the initiation of kidney replacement therapy (KRT), HFrEF and HFpEF also exhibited statistically different data comparing to those without HF. Specifically, HFrEF showed a HR of 2.14 (95%, 1.27-3.63), while HFpEF had a HR of 1.79 (95%, 1.25-2.56). The Kaplan-Meier analysis demonstrated a steeper descent curve for both survival and start of KRT for the HF group compared to the non-HF group (log-rank p &lt; 0.0001) over the study period. Within the HF group, the worst survival outcomes were observed in the HFrEF subgroup, followed by HFmrEF and HFpEF (log-rank p &lt; 0.0001).

Conclusion
Heart failure is a prevalent condition in CKD patients and worsens outcomes. Our analysis of real-world data suggests a threefold higher risk of mortality among for patients with HF, and a fivefold increase in the subgroup of HFrEF, comparing to patients without HF. Notably, preserved EF yielded a HR of 3.3 for mortality when compared to those without heart failure, underscoring the importance of clinical accurate assessment, since both entities may present with preserved ejection fraction in echocardiogram. Despite the study's sample limitations and the fact that it is unicentric, we believe this work holds significance as it highlights the importance of the establishment of different degrees of HF as it can change the prognosis in terms of mortality and progression to kidney replacement therapy in CKD patients. In addition to the established association between reduced EF and mortality, the HFpEF showed to exert a notable influence on outcomes comparing to patients without HF. This emphasizes the importance of not neglecting this entity, as it should treated appropriately.