RESUMEN
INTRODUCTION: The long-term evolution of clinical, echocardiographic, and laboratory parameters of cardiac function in patients with chronic heart failure (HF) with either reduced (HFrEF) or mildly reduced (HFmrEF) left ventricular ejection fraction (LVEF) is incompletely characterised. METHODS: We identified patients with chronic stable HF who presented at least twice to a university HF outpatient clinic between 1995 and 2021. Trajectories of NYHA functional class, LVEF, left ventricular internal end-diastolic diameter (LVIDD), NT-proBNP concentrations, and HF treatment over 10 years of follow-up were analysed using fractional polynomials. Analyses were repeated after stratifying patients according to aetiology (ischaemic vs. dilated) or HF category (HFrEF vs. HFmrEF). RESULTS: A total of 2,132 patients were included, of whom 51% had ischaemic and 49% had dilated HF. Eighty six percent and 14% were classified as HFrEF and HFmrEF, respectively. Mean LVEF was 28 ± 10%, and median NT-proBNP and estimated glomerular filtration rate values were 1,170 (385-3,176) pmol/L and 81 (62-100) mL/min/1.73 m2, respectively. Median follow-up was 5.2 (2.6-9.2) years. Overall, NYHA functional class and LVIDD trajectories were U-shaped, whereas LVEF and NT-proBNP concentrations markedly improved during the first year and remained stable thereafter. However, the evolution of HF parameters significantly differed with respect to HF category and aetiology, with greater improvements seen in patients with HFrEF of non-ischaemic origin. Improvements in HF variables were associated with optimization of HF therapy, notably with initiation and up-titration of renin-angiotensin-system blockers. CONCLUSION: This study provides insights into the natural history of HF in a large cohort of well-treated chronic HF outpatients with respect to subgroups of HF and different aetiologists.