It is estimated that 5.7 million Americans currently have heart failure according to the National Health and Nutrition Examination Survey (NHANES) [3]. This is projected to reach 8 million individuals by 2030. It is similarly estimated that 78 million individuals worldwide will have heart failure in 2030 [4]. Most estimates suggest the prevalence in the United States is 2–3 % of the general adult population [10, 16]. However, there are widely varying estimates in different reports. These differences are a function of the age sampled, the case definition, and the site (in- or outpatient) of case finding.

According to NHANES in 2009–2012, heart failure is a disease associated with aging. In the youngest adult age group (20–39 years), under 1 % are afflicted, while for those 80 years and above, over 10 % report the condition (◘ Fig. 6.4). Heart failure prevalence also affects men differently than women (◘ Fig. 6.5). As shown in ◘ Fig. 6.5, Blacks have significantly higher rates than Whites and men higher rates than women.

It is also clear that prevalence rose during the past decades. Curtis et al. using Medicare data (65 years and above) found prevalence of 90 per thousand person years in 1994 which rose to 121 per thousand person years in 2003 [15]. Data from the Kaiser Health Plan found the prevalence rising in their population for both men and women with men having a higher rate than women. Their rates range from 1.01 to 2.12 % of their patient population [14].

The study of a French population found a prevalence of 0.9 % for those aged 55–64 rising to 17.4 % prevalence in those 85 years and above [16]. A more recent study of Medicare on the prevalence of 13 % as shown in ◘ Table 6.1, in a 5 % sample of Medicare records, prevalence is steadily rising [15].

There are a number of factors thought to be acting in increasing prevalence in the setting of flat or declining incidence. Better recovery from acute myocardial infarction is cited as one [3], but there is also improved survival from sudden death episodes, better methods of treatment, and a better recognition of the disease [3]. All of these factors improve survival; however, part of the increased prevalence may be a function of a so-called “lead time bias” where more sensitive diagnostic measures lead to a discovery of earlier cases which have a longer life post diagnoses.

Heart failure is a deadly disease. Death is frequently associated with other illnesses, but in many cases heart failure is the underlying cause. The analysis of data from Scotland finds that heart failure has a higher mortality rate than the four leading causes of cancer combined [17]. The 2008 death certificate data found 88/100,000 population mentions of heart failure with 17/100,000 population as the underlying cause of death [18]. Data from Olmsted County found 60 % 5-year mortality after diagnosis [19]. Similar data are observed in other industrialized countries including the Netherlands, Australia, Scotland, and Canada [19–22]. Heart failure is frequently associated with sudden death and increases with increasing NYHA severity classification [23].

Heart failure rates as underlying cause of death by race are shown in ◘ Fig. 6.6. Blacks have the highest rate followed by Whites, American Indians, Hispanics, and Asians. Men have higher rates of heart failure as the underlying cause than women. Heart failure death is strongly associated with age as shown in ◘ Fig. 6.7. Heart failure diagnosed in an inpatient admission has a significantly worse prognosis than heart failure diagnosed as an outpatient [24]. However, the prognosis in both is poor at 5 years. There is 90 % mortality at 10 years [5].

The trends for heart failure mortality have improved. This begins within hospital mortality where a 10.9 % rate in 1980–1984 fell to 6.5 % in 2000–2004 [25]. However, 30-day mortality improvement after hospitalization was less dramatic with 12.8 % mortality in 1993 and a 10.7 % mortality in 2006. Clearly, more patients were dying at home [26]. Overall, Medicare data in all adults 65 and older hospitalized found an 8.5 % mortality in 1993 and 4.3 % in 2006 [26]. Similar trends were observed elsewhere including Australia where 1-year mortality fell from 22 % in 1990–1993 to 17 % in 2002–2005 [20]. Similar declines were noted in Sweden and Scotland [22, 27].

Heart failure is a deadly disease with few living beyond 10 years after diagnosis. Improved acute care has reduced in-hospital mortality. Prolonged care has also reduced mortality. The combination has resulted in increased prevalence in heart failure under the care of health systems .

With the widespread availability of imaging to measure ejection fraction, it became apparent that many patients with signs and symptoms of heart failure did not have reduced ejection fraction associated with pump failure. This was initially termed diastolic heart failure in the clinical presentation and was associated with an ejection fraction above 45 % [19]. The pathologic findings associated with preserved ejection fraction are concentric remodeling of the left ventricle and left ventricular hypertrophy [28]. In recent years, considerable work has occurred to better define heart failure with preserved ejection fraction (HFpEF) in comparison to those patients with reduced ejection fraction (HFrEF) . Depending on the inclusion criteria, it is estimated that 13–74 % of all heart failure is HFpEF [10, 29]. When ascertaining prevalence, definitions become an important issue. Various authoritative sources have suggested anywhere from an ejection fraction of less than 35 % to less than 45 % defines HFrEF [7].