Heart failure (HF) is a serious public health problem that, despite advances in both pharmacological and non-pharmacological treatment and in the management of the condition, affects a significant number of people and is associated with high mortality and morbidity.1,2 It is a clinical syndrome characterized by symptoms and signs caused by objective cardiac dysfunction.1

The main risk factors predisposing to HF among the general population include coronary artery disease, hypertension, hypercholesterolemia, diabetes, smoking and obesity.3 The presence of multiple comorbidities is one of the main determinants of both prognosis and quality of life.4–6

Several studies have been published on the prevalence of HF. However, due to differences in populations and in the criteria used for both defining and diagnosing HF, the results obtained are divergent and there is a lack of agreement on estimates of prevalence and incidence of the syndrome.1,4

Nevertheless, the prevalence of HF in developed countries is estimated to be around 2% in the adult population, and the incidence data suggest that HF affects 5-10 people in every 1000 per year. Various studies have indicated that both frequency measures rise with advancing age.2,5 In Portugal, the EPICA (Epidemiology of Heart Failure and Learning) study suggested that the overall prevalence of chronic HF in the adult population was 4.36%, reaching 12.67% in those aged 70-79 years and 16.14% in those aged 80 and over.5 The syndrome has a significant economic impact; in developed countries, the direct costs of HF account for about 2% of total healthcare budgets.3 Globally, it is estimated that this figure amounted to 102 billion euros in 2012, in a sample that included 92.4% of all countries and 98.7% of the world's population at the time.7

With the aging of the Portuguese population, together with the increased survival of patients with coronary artery disease, the impact of the syndrome is expected to increase substantially.8 This publication aims to assess and forecast the most likely prevalence scenario and the associated consequences if no measures are taken to reduce the impact of the syndrome in the coming years.

Among the various factors that contribute to the increase in the prevalence of HF, aging plays a central role. Resident population projections suggest Portugal's population will decline because of a decrease in the number of births. As a result, a fall in the number of HF patients would also be expected. However, the aging of the population works against this expectation, and the number of HF patients is likely to rise to 494141 by 2060. This projection indicates that, by 2018, the number of patients over the age of 60 (312649) will be greater than the figure previously estimated in the EPICA study for adults with HF of all ages (around 264000).5

Similar results were obtained by a study carried out in the USA that used a similar methodology to this analysis.11 The American study found that the number of HF patients in the country would be around eight million in 2030, corresponding to 46% more affected individuals than in 2012. In Portugal, the number of adult HF patients in 2035 is expected to be around 30% above the figure for 2011. Given the expected aging of the population in the USA, it is estimated that the number of patients over the age of 80 in 2030 will be 66% higher than in 2012.11 In Portugal, the increase between 2011 and 2035 for this age group is expected to be similar, at around 73%. Considering the above, demographic changes foreshadow a rapid increase in the number of HF patients.

An analysis of the projections by HF subtype indicates that by 2018 there will be 126898 individuals with HF with preserved systolic function, most of whom will be elderly and female, in agreement with the existing literature.12 Given the population trends identified by INE, the prevalence of this HF subtype is expected to increase. It should be noted that there is less consensus, and therefore more of a challenge, regarding the diagnostic criteria for HF with preserved LVEF. Furthermore, there is still no treatment capable of objectively reducing mortality in this entity, unlike HF with reduced LVEF.2 An epidemiological change in HF is probably underway, given that various studies have found that HF with preserved LVEF is on the rise. This is at least partially attributable to the aging factor and to the increase in the risk factors and comorbidities that accompany and contribute to the development of HF, and also to a lower prevalence of HF with reduced LVEF.13

The NYHA functional classification is one of the strongest independent prognostic predictors for HF.2,4 By 2035, the number of outpatients in NYHA class III and class IV is expected to be over 136000. These more serious stages of the disease are associated with more complex patient management and a greater impact on the national health system (NHS), as a consequence of increased hospitalizations and rises in morbidity and mortality. The available data show that hospitalization accounts for up to 80% of the costs of the syndrome. Furthermore, the number of patients in class IV was probably underestimated by the EPICA study, given that the study focused on outpatients, and is probably much higher, since patients at this stage of the disease are more likely to be treated in a hospital setting.

A number of studies that examined trends in HF hospitalization over the years have found that, for the elderly, hospitalizations reached a peak in the 1990s but have since fallen off. Factors that contribute to fewer hospitalizations include reduced and/or improved medical control of risk factors such as hypertension and smoking, a decrease in the incidence of acute myocardial infarction, the establishment of multidisciplinary HF management programs, and an increase in the number of patients who are diagnosed earlier and receive treatment through the primary healthcare system.4,14,15

Nevertheless, the fact that HF is the major cause of hospitalization in the over-65s attests to the impact of this syndrome in developed countries.16,17 In Portugal, a study using the national database of Diagnosis Related Groups (DRG) assessed trends in HF hospitalization between 2000 and 2015 and found that the number of patients hospitalized for HF doubled, particularly in the 66-80 and over-81 age groups. There was a strong correlation between these figures and the attendant risk factors.18 Given, also, that the Portuguese population is aging, there is likely to be a significant rise in the number of hospitalizations and in the direct medical costs of HF treatment, unless specific preventative steps are taken and practices altered. In view of the 2015 report on Cerebro-Cardiovascular Diseases, this projection is very much in line with expectations for 2018, 2035, 2060 and 2080, when the numbers of patients discharged after an acute HF episode are projected to be 16708, 20157, 20756 and 18354, respectively.10 The same report also shows that in-hospital mortality due to HF fell by 9.90% between 2010 and 2014.10 Schmidt et al. assessed the trend for HF hospitalizations and mortality rates over the last 30 years in a Danish cohort and found that one-year and one- to five-year mortality also declined consistently between 1983 and 2012, falling more than 40% overall.15 It should be noted that, in its calculation of HF hospitalizations, the report on Cerebro-Cardiovascular Diseases, which made use of the DRG coding base, only took into account the DRG code for the main diagnosis (ICD-9-CM: 428). As HF hospitalizations may be coded by more than one identifier and as the HF code may appear as a secondary diagnosis if the main reason given for hospitalization arose from the acute episode itself (infection or arrhythmia, for example), this report is unlikely to accurately reflect the actual number of hospitalized HF patients, which is very likely higher.10,19

Moreover, there are no data available regarding the total number of HF hospital admissions in Portuguese emergency departments. Readmissions are a significant factor in HF management. Hospitalization is followed by readmission 30 days later in around 24% of cases,20 and this rises to 50% after six months.21 There is thus a critical need to assess this indicator in Portugal, since a reduction in readmission rates could lead to lower costs and improved healthcare provision and is an important focus in performance indicators for both public and private payers.22

Given the data presented above, there is a firm conviction that the prevention and early diagnosis of HF, based on an understanding of its epidemiology, could have a significant effect in terms of improving quality of life and mortality and simultaneously reducing healthcare costs.8,17,23

It is also important to optimize the therapeutic approach to HF patients with reduced LVEF. The ESC Heart Failure Long-Term Registry, maintained by the European Society of Cardiology, shows that between 2011 and 2013, despite the widespread usage of the disease-modifying pharmacological treatments recommended in the guidelines, only a third of patients received the maximum tolerated dosage deemed appropriate.24 The European SHAPE study on perceptions of HF found that general practitioners had low levels of understanding of the syndrome and of the treatment options.25 Furthermore, the general public appeared to be largely unaware of the nature, seriousness, therapeutic options and associated costs of HF. Thus, it is unlikely that either the general public or healthcare professionals will pressure the health authorities to take appropriate action.25

The importance of heart failure is also somewhat underestimated in Portugal, by both health professionals and decision-makers. This is reflected in the lack of definition of HF care flows and structures at various levels of the NHS, and also in the lack of communication between the various parties involved in HF treatment.8

The difficulty that the general public and patients have in recognizing both the symptoms and the seriousness of the syndrome means that there are often delays before medical advice is sought. HF awareness needs to be improved, particularly regarding identification of the syndrome and recognition of its etiology. This would then encourage patients to change their lifestyles and help bring down risk.

A key priority, therefore, must be proper management of the patient and the disease through the National Health Plan, if we are to turn these projections around and reduce the associated burden.8,17,26

These projections are based on the prevalences estimated almost 20 years ago in the EPICA study. No additional recent studies of HF prevalence have been carried out in Portugal, which is why we made use of the EPICA prevalence figures and INE population estimates.

Bearing in mind that this analysis is based on the EPICA data, the limitations of that study also pertain here. Prime among these was the fact that the sample consisted of patients followed through the primary healthcare system and not the population in general. Given that such patients will tend to be less well than the population in general, it is plausible to assume that they will suffer from more serious heart disease. Furthermore, it is probable that the number of patients in NYHA class IV has been underestimated, given that such patients usually receive in-hospital treatment and the EPICA study looked at outpatients only. Moreover, as the population in general was not assessed by the EPICA study, the numbers obtained are presumably lower than the real figures.

Finally, it should be noted that INE projections are constrained by the structure and composition of the population at the starting point and also by the different fertility, mortality and migration patterns used in each of the hypotheses. It should also be borne in mind that the longer the projection period, the greater the associated uncertainty.

HF is one of the main causes of morbidity and mortality. It primarily affects the elderly and has a significant impact on the patient and on society in general.13,17

The demographic changes that are expected to ensue from the marked aging of the population suggest that a considerable number of Portuguese will be affected by the syndrome in the coming years. The actual number may double from current levels to around half a million by 2035. The real prevalence of HF in Portugal today is unknown, which is why it is so important to arrive at an estimate that is based on epidemiological data. This is crucial to healthcare decision-making and resource allocation.17

In addition to the large number of patients expected, hospitalizations and mortality associated with this syndrome are likely to significantly increase the economic impact of HF. It is critically important to raise awareness of the syndrome, to facilitate early diagnosis and patient referral. This will result in better HF management and consequently improved patient lifestyles and lower disease management costs.

The possibility of forecasting, as accurately as possible, the expected increase in the number of patients with HF and its consequences in the short, medium and long term is crucial to a proper understanding of the burden and costs of the disease and the development and implementation of strategies that could reverse these trends to some degree and thus significantly reduce the anticipated epidemic.

Cândida Fonseca is a consultant for Novartis, Orion, OM Pharma, Bayer and Servier (companies that develop and market treatments for heart failure and its associated comorbidities) and sits on the executive and scientific committees of clinical research studies run by Novartis, Servier, Orion, Bayer and OM Pharma. She has also received fees for speaking on heart failure from Novartis, Servier and Orion. Inês Araújo has received speaker fees from Servier, Novartis and Orion. She is also a co-investigator for HF clinical studies run by Servier, Novartis and Bayer. Fátima Ceia has no conflicts of interest to declare. Daniel Brás is employed by Novartis Farma S.A., Porto Salvo, Portugal.