Low rate of worsening renal function after 2 years of treatment with edoxaban in patients from the ETNA-AF-Europe study
Authors: Gwechenberger M , Baron-Esquivias G , De Vries T A C , Siller-Matula J , De Groot J R , De Caterina R , Kirchhof P ,   ETNA-AF-Europe
Published: October 2021

Abstract

Background
Use of vitamin K antagonists (VKAs) is associated with a crude event rate of 23% per year for worsening renal function (WRF). Although non-vitamin K antagonist oral anticoagulants (NOACs) have been associated with a lower risk of longitudinal decline in renal function compared with VKAs, available evidence on renal function decline in patients using NOACs is still limited. Furthermore, renal function is a dose reduction criterion for NOACs, which poses an important question about how physicians should treat patients whose renal function worsens over time.

Purpose
To evaluate the degree of renal function decline in AF patients treated with edoxaban after 2 years of follow-up, and to investigate clinical outcomes of patients with vs without WRF in the ETNA-AF-Europe study.

Methods
ETNA-AF-Europe is a multinational, multicentre, observational, post-authorisation safety study conducted in 825 sites in 10 European countries. Results are based on a data snapshot taken on 26th October 2020 which include data up to 2 years of follow-up. Patients were excluded from the analysis population if data to calculate estimated glomerular filtration rate [eGFR] were not available for at least one of the follow-up time-points of 1-year and 2-year. We categorised patients (n=9084) into two subgroups: 1) those with WRF (i.e. ≥25% decline in eGFR from baseline; n=918), and 2) those without WRF (n=8166). eGFR was estimated using the Cockcroft-Gault formula. Baseline characteristics and annualised event rates including 95% confidence intervals were analysed using descriptive analyses.

Results
Of the 13,417 patients in ETNA-AF-Europe who were included in the 2-year follow-up analysis, 9084 were included in this subgroup analysis, of whom 56.2% were male. Baseline eGFR were similar between patients with and without WRF when comparing across the different renal function categories (Table 1). The majority of the edoxaban-treated patients did not experience WRF (89.9%) during the 2 years of follow-up. The proportion of patients with WRF (10.1%) were older, more often frail and had higher rates of underlying comorbidities, such as diabetes, hypertension and heart failure (Table 1). Patients with WRF had higher annualised event rates of all-cause and cardiovascular death than those without (3.78% vs 1.90% and 2.06% vs 0.92%, respectively). Major bleeding and stroke rates were low, but numerically higher in patients with renal worsening compared to those without WRF (Figure 1). Intracranial haemorrhage rates remained low (0.17% vs 0.19%; Figure 1) in both subgroups.

Conclusions
This subgroup analysis provides real-world evidence for a low risk of WRF in AF patients treated with edoxaban over a 2-year period. Patients with WRF had higher mortality than those without, as well as numerically higher major bleeding and stroke rates. Importantly, intracranial haemorrhage rates remained low irrespective of WRF.

Funding Acknowledgement
Type of funding sources: Private company. Main funding source(s): Daiichi Sankyo Europe GmbH /