Heart failure (HF) is a major clinical and public health problem worldwide, associated with significant healthcare expenditure, morbidity, and mortality, particularly in individuals aged ≥65 years [1]. HF was identified as an emerging epidemic as early as 1997 [2]. The prevalence of heart disease increases with age [3]; therefore, HF is set to be a growing public health issue as the population ages.

It has been estimated that up to ~3% of the general population, and 10% of the elderly, may be living with HF in the twenty-first century in the USA [3]. The overall incidence of HF has been estimated to be ~1–2 cases per 1000 individuals, based on data from large, prospective, population-based studies conducted in the USA in the 1990s [4, 5]; however, few studies provide recent estimates of the prevalence and incidence of HF in European populations. A cross-sectional study of individual patient data from Sweden estimated HF prevalence and incidence for the entire Swedish population, adjusting for demographic composition in 2010. The overall prevalence of HF was 2.2%, while the incidence was 3.8/1000 persons at risk [6]. In a cross-sectional, population-based study in Germany, the overall age-standardized prevalence of symptomatic chronic HF was 7.7% for men and 9.0% for women [7]. Finally, in a recent, large, real-world study of data from three German statutory health insurance (SHI) providers, the age- and sex-standardized prevalence of HF was estimated at 1.7% in 2004, 1.9% in 2005, and 1.7% in 2006 [8].

HF is the most common cause of hospital admission and the third most common cause of death in Germany [9]; between 2000 and 2013, the number of hospitalizations for HF increased from 239,694 to 396,380 cases [10]. HF is also associated with a substantial financial burden. The condition accounts for ~1–2% of direct health costs in Western industrialized nations, and ~1.1% of direct health costs in Germany, where the direct hospital costs (€2.9 billion in 2006) are primarily driven by the cost of inpatient stays [9]. A recent systematic review found that direct medical costs for patients with chronic HF were €3417–5576 per patient per year. Furthermore, treatment costs were shown to increase with disease progression [11]. This confirms the high financial impact that HF has on the German healthcare system.

We conducted a retrospective analysis using data from the Health Risk Institute (HRI) database to evaluate the epidemiology of HF in a representative sample in Germany. We further aimed to evaluate selected predictors of the risk of hospitalization and death in patients with HF, and to describe the way in which patients newly diagnosed with HF were diagnosed and treated.

Of the 4,088,854 patients in the representative subset of the database used, 3,132,337 had observable data from 1 January 2009 to 31 December 2013, had not died before 1 January 2011, and were, therefore, included in the study.

There are few studies providing up-to-date estimates of the prevalence and incidence of HF in Europe [6, 7]; the findings of this large, retrospective database study expand our knowledge in this area and support the notion that estimates of HF in Germany are continuously growing [8]. Considering that over 55% of patients with HF were hospitalized in the 2-year period of the study, and over one-fifth of newly diagnosed patients died within the same time frame, these findings underline the relentless burden of HF in Germany.

This study estimated the prevalence of HF to be 3.96% and the incidence to be 655 new cases per 100,000 persons at risk; this means that 524,000 new cases of HF are expected to be diagnosed per year in Germany. These findings are broadly in line with reports from other European countries and the USA, where prevalence ranges of ~1–3% [3, 7, 8] and incidence ranges of 100–500 per 100,000 persons at risk in the general population, unadjusted for age, have been reported [4, 8].

In our analyses, the prevalence and incidence of HF increased with age, consistent with reports from large population-based studies in the Netherlands [21] and the USA [5]. The incidence of HF was higher in men than in women when examining individual age groups, although this was not the case when looking at overall incidence. This may be explained by the finding that there were more women than men in the older age groups, probably reflecting higher life expectancy in women than in men [22]. The incidence of HF also varied by NYHA classification; the incidence of NYHA class I HF was markedly lower than that of NYHA classes II–IV. This is probably owing to the fact that many patients with NYHA class I HF do not exhibit symptoms attributable to heart disease [23] and therefore remain undiagnosed until symptoms occur.

The financial burden of HF on healthcare systems is dominated by the direct hospital costs of inpatient stays [9, 11], and treatment costs have been shown to increase with disease progression [11]. In the current study, HF was the most common reason for hospitalization of patients with newly diagnosed HF, and the risk of hospitalization increased with increasing age. Importantly, over 80% of these patients suffered from comorbidities that are associated with accelerated disease progression [24]. Furthermore, 16.3% of patients with HF, and over one-fifth of newly diagnosed patients, died within the 2-year follow-up period. As expected, mortality increased substantially with increasing age and NYHA class; more than half of all patients newly diagnosed with HF of NYHA class IV died within 2 years of diagnosis. This underlines the need for appropriate management strategies depending on disease severity; on one hand, palliative strategies for patients with advanced HF need to be carefully considered, but on the other hand, earlier diagnosis and improved management of patients in their most vulnerable phases—immediately after diagnosis and/or discharge from hospital—are needed.

According to our data, office-based family practitioners currently diagnose the majority of patients with HF in the German healthcare system, and remain their principal provider of pharmacotherapy. However, general practitioners face major obstacles in establishing a diagnosis of HF, because they often lack time, expertise, or access to echocardiography [25]. Accordingly, only 20.9% of patients have a NYHA class assigned, which is mandatory to apply guideline-recommended strategies. Because prognosis for patients with HF critically depends on early diagnosis and risk-adapted treatment and care (especially in the 6–12 months after diagnosis), our data strongly underscore the need for more appropriate strategies to apply the evidence-based diagnostic and care algorithms in the German healthcare system. A more systematic involvement of cardiological expertise in diagnosis and in the adoption and up-titration of HF therapy seems intuitive, as does the engagement of dedicated nursing staff (both in hospitals and outpatient practices) to support, accelerate, and amplify such efforts. Further studies, preferably including analyses of regional healthcare providers rather than selected practices, are needed to quantify the effectiveness of patient pathways in terms of costs and patient outcomes.

The high prevalence and incidence of HF, the substantial mortality in the 2 years following diagnosis, and the high level of associated morbidity observed in this study underline the heavy burden that HF imposes on the German healthcare system. This highlights the urgent need for improving diagnosis and treatment of this disease. Close collaboration between all physician specialities and healthcare sectors is essential to improve the prognosis for patients with HF in Germany today.