An update on global epidemiology in heart failure

Heart failure (HF) is a heterogenous and life-threatening syndrome that affects more than 60 million individuals globally and is characterised by severe morbidity and mortality, poor quality of life, and a high burden on the healthcare systems in terms of resource use and expenditures.1 The 2019 Heart Failure Association (HFA) ATLAS provided estimates concerning important aspects of HF epidemiology in Europe and reported a HF prevalence ranging from ≤12 in Spain and Greece to over >30 per 1000 persons in Lithuania and Germany.2 The prevalence of HF in the United States was estimated at 2.4% in 2012.1 Prevalence estimates in Asia range between 1.3% and 6.7%.1 Notably, the prevalence of HF is further projected to increase worldwide due to the aging of populations, improved treatments for ischaemic heart disease, and the availibility of effective evidence-based therapies prolonging life in patients with established HF, most notably HF with reduced ejection fraction (HFrEF).1 Data on the prevalence of the different HF phenotypes stratified by EF [HFrEF, HF with mildly reduced ejection fraction (HFmrEF), and HF with preserved ejection fraction (HFpEF)] are limited due to the lack of an ejection fraction (EF) assessment in numerous large-scale registries and administrative datasets. Epidemiological data across the EF spectrum are mostly derived from registries in Western countries, where HFrEF (EF <40%) seems to affect ∼50% of HF patients, whereas ∼20–25% each might have HFmrEF or HFpEF.1 More specifically, in the Get With The Guidelines-HF registry from the United States, estimates were 39% for HFrEF (EF <40%), 14% for HFmrEF (EF 40–50%), and 47% for HFpEF (EF >50%).3 In the Swedish HF registry, 56% had HFrEF, 21% HFmrEF, and 23% HFpEF.4 In Asia, the prevalence of HFpEF seems to be higher compared with Western countries (35–45%).1 Notably, the prevalence of HF has been observed to be increasing for HFpEF, but to be stable or even declining for HFrEF, likely due to enhanced treatment and prevention of ischaemic heart disease (Figure 1). There is lack of evidence on HF prevalence in Africa and South America. Current data suggest that HFpEF may become the most common HF phenotype in the near future. Epidemiology of heart failure worldwide. CV, cardiovascular; HFpEF, heart failure with preserved ejection fraction; HFrEF, heart failure with reduced ejection fraction. Data on incidence are even more limited than those on prevalence. In Europe, in the HFA ATLAS, the median annual incidence of HF was 3.2 per 1000 person-years (ranging from <2 in Italy to ≥ 6 in Estonia and Germany in 2018–2019).5 Between 2000 and 2010, the age- and sex-adjusted incidence of HF declined from 3.2 to 2.2 per 1000 person-years in the United States.6 Notably, 52.5% of patients with incident HF in the Olmsted County cohort in the US had HFpEF (EF ≥50%) (Figure 1). For both HFrEF and HFpEF, the age- and sex-adjusted incidence of HF decreased significantly (−37%), but more for HFrEF (−45%) than HFpEF (−28%) and more for females (−43%) than males (29%).6 In a US community-based study, HFmrEF accounted for ∼10% of incident HF.7 HF incidence was 0.7 per 1000 population in 1997 in Hong Kong, which was 20 per 1000 population for females and 14 per 1000 population for males in >85 years old people.1 In South America, data on incidence of HF are scarce, and in Africa, it is almost completely lacking. The prognosis of HF has improved over time, but mortality remains high.1 In the European Society of Cardiology (ESC) HF-Longterm (LT) registry, 1-year mortality was 23.6% for acute HF and 6.4% for chronic HF in 21 European countries between 2011 and 2013.8 Another analysis from the ESC-HF-LT registry including 9,134 ambulatory HF patients showed that 1-year mortality was highest in HFrEF (8.8%), followed by HFmrEF (7.6%) and HFpEF (6.3%).1 Between 2005 and 2009 in the United Satates, the median survival of patients admitted with worsening HF was 2.1 years, and 5-year mortality was 75.4%, with a comparable 5-year mortality in patients with HFrEF vs. HFpEF (75.3% vs. 75.7%).1 Among patients with chronic HF, cardiovascular death (49%) was the primary cause of death at 1 year in the ESC-HF-LT registry (Figure 1). Notably, cardiovascular death was more common in HFrEF (53%) compared with HFmrEF (50%) and with HFpEF (47%).1 Conversely, non-cardiovascular death was higher in HFpEF (30.7%) vs. HFmrEF (27.8%) vs. HFrEF (20.1%) at 1 year.1 In an Australian meta-analysis enrolling >65 000 hospitalized patients for HF, 30-day mortality was 8% and 1-year all-cause mortality was 25%.1 Hospitalizations in patients with HF were common, particularly in males, and the majority (63%) of hospital admissions in patients with HF were due to non-cardiovascular causes.6 The total number of hospitalizations was reported to be similar regardless of EF, with some evidence of a higher risk of cardiovascular hospitalizations in HFrEF and non-cardiovascular hospitalizations in HFpEF.6 The financial burden of HF on global healthcare systems and economies is significant, and it is likely to increase as the prevalence of HF is expected to increase in the future. In the Western world, annual healthcare costs for HF patients amount up to €25 000.1 Direct costs [inpatient treatment, (re-)hospitalizations] account for the majority of healthcare costs in patients with HF (Figure 1).9 Increasing numbers of HF hospitalizations, particularly among women, might suggest a later patient presentation and the lack of effective treatments in HFpEF.1 Direct and indirect costs are predicted to increase dramatically as a result of major demographic changes (e.g. aging of the population and global population growth) and the overall growing prevalence of HF, together with an ageing population. While data on healthcare costs for each HF phenotype are limited, HFpEF was identified to have a greater impact on hospitalization-related costs compared with other HF phenotypes, which might be explained by the higher burden of comorbidities in HFpEF.1 Since HFpEF is projected to be the most common form of HF in the near future, a main goal is focusing on establishing life-saving treatments in HFpEF over the next years. Currently, only empagliflozin has been shown to improve morbidity/mortality in HFpEF.10 Further, a better understanding of the causes of hospital admission and re-admissions is needed to set strategies aiming to improve outcomes in patients with HF. Finally, epidemiological data on HF in developing countries are highly needed, due to the well-known geographical differences in HF aetiologies and outcomes.