p.16 抽出テキスト

variations.12,13 Both the incidence and prevalence of HF are increasing with age and risk-factor burden, with wide variation depending on the population and setting studied and the diagnostic criteria used.14 In addition, several factors, such as level of education, income, neighbourhood deprivation, climate, and air pollution, influence the risk of HF, contributing to varying epidemiology worldwide.13 In European countries, current prevalance-estimates range from 12–58 cases per 1000 people.15 As a result of the growing cohort of older people in Western populations, the crude incidence of HF has been increasing and is currently 2–13 per 1000 person-years in Europe (ranging from <1 per 1000 person-years for people aged 45–54 years to >12 per 1000 person-years for people aged >74 years).16,17 However, age-adjusted HF incidence rates have been declining over the past three decades, probably because of better risk-factor control and treatment of CV conditions.15,17,18 Among younger adults, incidence rates of HF appear to be either increasing or stagnating. There are several possible explanations for this, including (i) a greater burden of CV risk factors, (ii) increasing numbers of patients with congenital heart disease reaching adulthood, and (iii) a change in surveillance patterns.16,19,20 Furthermore, the mortality of HF has improved, which has led to a higher prevalence of HF.13

3.2.1 Epidemiology of heart failure phenotypes

In population-based samples, nearly half of all HF cases have HF with preserved ejection fraction (HFpEF), and this proportion may be increasing due to better treatment of coronary artery disease (CAD) and the rising burden of hypertension, obesity, and other HFpEF risk factors.21 Patients with HFpEF are older and are more often female. The Swedish HF registry reported an average age at HFpEF onset of 77 years with 55% female.22 In patients with heart failure with reduced ejection fraction (HFrEF), 71% were male and the mean age at onset was 72 years.22 Several subtypes of HFpEF have been suggested, with up to 50% of patients having a predominantly metabolic/obesity subtype [younger, higher body mass index (BMI)] in some regions, and up to 50% with a predominantly ageing, vascular subtype [older, stiff arteries, high prevalence of chronic kidney disease (CKD)] in other regions.23,24 Heart failure with reduced ejection fraction is often subdivided into ischaemic vs non-ischaemic aetiologies, with approximately half of all cases being considered ischaemic.

3.2.2 Natural history and prognosis

Although the mortality rates after HF onset have improved considerably over the past three decades, the 5-year overall survival rates are still <60%.25,26 For younger patients, data from Denmark suggest survival has improved with contemporary management, with a current 5-year mortality rate of 15% for patients <65 years and 39% for patients aged 65–79 years.25 In patients ≥80 years, improvements in mortality have also been observed, although these improvements are not as pronounced as those observed in younger patients, partly due to a greater burden of comorbidity and a greater proportion of non-CV mortality in the elderly.17,25,27 Mortality may be lower in HFpEF than HFrEF, but overall differences are small as patients with HFpEF are considerably older, and the risk of hospitalization is similar.28,29 Patients diagnosed with HF in an outpatient setting have better prognosis than patients diagnosed during a HFH, and patients with repeated HFH have a particularly high risk of mortality.30,31

The overall burden of HF as well as HFH can be expected to rise over the next few decades due to greater survival, an ageing population, and greater prevalence of risk factors and obesity in the younger population.

3.3 Classifications

3.3.1. Classification based on left ventricular ejection fraction Traditionally, HF has been divided into distinct phenotypes based on the measurement of LVEF. In the 2021 ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure, three different HF phenotypes were identified: HFrEF (LVEF ≤40%); HF with mildly reduced ejection fraction (HFmrEF, LVEF 41%–49%); and HFpEF (LVEF ≥50%).3 The rationale behind this classification relates to the inclusion criteria of the trials of therapies that improved outcomes in patients with HF and LVEF ≤40%. The HFmrEF phenotype was introduced to focus on patients usually not included in HFrEF trials. The nomenclature was changed from ‘mid-range’ to ‘mildly reduced’ to highlight that patients with HFmrEF are similar to patients with HFrEF in terms of both clinical characteristics, outcomes, and response to treatments.32,33 Patients with HFmrEF have similar underlying aetiology of HF to patients with HFrEF, and the pathophysiology of HFmrEF is more similar to HFrEF (reduced contractility and systolic dysfunction) than HFpEF (increased stiffness and diastolic dysfunction).34 In addition, the efficacy of medical treatment of HFmrEF is more similar to HFrEF than HFpEF.35–45 Finally, it is important to consider LVEF trajectories, as many patients with LVEF 41%–49% may experience a deterioration in LVEF.46 The Task Force for the 2026 ESC Guidelines for the management of heart failure has eliminated the phenotype of HFmrEF and reclassified HF based on a pathophysiological classification of HF, including two distinct phenotypes: (i) HFrEF: characterized by LVEF <50% and symptoms and/or signs of HF. (ii) HFpEF: characterized by LVEF ≥50% and symptoms and/or

signs of HF and objective evidence of cardiac structural and/ or functional abnormalities consistent with the presence of left ventricular (LV) diastolic dysfunction/raised LV filling pressures, supported by raised natriuretic peptides.

Using a single LVEF value as cut-point for distinguishing HFpEF and HFrEF is somewhat arbitrary and has to be evaluated in the clinical situation, as there is variability in measurement depending both on the modality and the interpreter. Furthermore, LVEF may be falsely high in certain situations, e.g. mitral regurgitation (MR). Natriuretic peptides may be used as supportive evidence for the diagnosis of HF. Importantly, drug and device therapies can lead to positive LV reverse remodelling in patients with HFrEF and, thus, improvement of LVEF. Patients with HFrEF and improved LVEF have a more favourable prognosis. However, it is important to ensure that these patients are still managed with optimal medical therapy except for selected patients. The current definition of improved LVEF requires an increase of at least 10% in LVEF (absolute) and must be at least above 40% (often normal).47 Downloaded from academic.oup.com/eurheartj/advance-article/doi/10.1093/eurheartj/ehag100/8766302 by guest on 31 August 2026