Real-World Use of ARNI Within GDMT in HFrEF Patients with and Without Atrial Fibrillation: A Retrospective Analysis of Cardiac and Renal Functions and Clinical Outcomes.

The aim of this study was to describe changes in estimated glomerular filtration rate (eGFR), left ventricular ejection fraction (LVEF) and clinical outcomes in a real-world cohort of patients with heart failure with reduced ejection fraction (HFrEF) and atrial fibrillation (AF). A total of 321 patients (67 [58-74] years old, 19.3% females) were included; 134 (41.7%) had AF. AF patients were less frequently prescribed angiotensin receptor-neprilysin inhibitor (ARNi), with no differences concerning sodium-glucose transport protein 2 inhibitors (SGLT2is) and had lower median baseline eGFR values. At 6- and 12-month follow-ups, renal function declined similarly in both groups, with no difference in the proportion of patients experiencing an eGFR decrease of ≥30% from baseline. Regarding cardiac remodeling, patients without AF showed a higher proportion of individuals with an LVEF improvement of ≥10% from baseline, however with no differences between groups in LVEF final recovery. During a median follow-up of 582 (339-1481) days, AF patients showed a higher risk of composite outcome (aHR, 95% CI: 2.12, 1.16-3.86) and of hospitalization for heart failure (hHF) (2.80, 1.44-5.46), without differences in all-cause death. Delta eGFR changes with at least a 30% decline in eGFR were associated with a higher risk of the primary endpoint. Despite lower baseline renal function, AF patients exhibited similar LVEF improvement and renal decline, which emphasizes the importance of guideline-directed medical therapy. AF was associated with a higher risk of adverse events, primarily driven by hHF.