Heart and Metabolism

Prevalence, increase, and costs of heart failure

Paul Mohacsi, Giorgio Moschovitis, Hildegard Tanner, Otto M. Hess, Roger Hullin
Cardiology, Swiss Cardiovascular Center Bern,
University Hospital (Inselspital), Bern, Switzerland
Correspondence: Dr Paul Mohacsi, Cardiology, Swiss Cardiovascular Center Bern,
University Hospital (Inselspital), 3010 Bern, Switzerland.
Tel: +41 31 632 4464, fax: +41 31 632 4299, e-mail: paul.mohacsi@insel.ch

Introduction
Heart failure is recognized as a major and escalating public health problem in industrialized countries with aging populations. It is therefore of utmost importance to carry out epidemiologic and economic investigations into heart failure. Morbidity in heart failure patients, measured as quality of life or hospitalization rate, is high; if the heart failure is in an advanced stage and untreated,[1] the mortality rate in these patients is comparable to that in malignant neoplasia.[2] Heart failure patients may die as quickly as those suffering from pancreatic tumor and their suffering is probably no less. Nobody would question the necessity of investigating patients with a suspected malignancy using expensive CT or MRI technology. Measurement of sometimes questionable tumor markers is widely accepted, as are the costs of these treatment strategies, even in hopeless cases. Cancer patients receive treatment even at an advanced age.
Unfortunately, patients with heart failure are not managed in the same way as those with carcinoma. It is acknowledged that diagnostic evaluation and guideline-based treatment are not sufficiently widespread.[3–5]
Epidemiologic data on heart failure are available[6–9] but are incomplete, for example with respect to the speed of the rising prevalence, which is certainly partly due to the increasing number of elderly. With heart failure, we may face a new medical challenge which may surpass epidemiological problems such as HIV or BSE. National and international heart failure registry data will help us to assess the magnitude of the epidemic and enable us to influence colleagues who do not adhere to heart failure guidelines, as well as health care insurance providers, administrators, and politicians.[10]

Prevalence
Any attempt to describe the epidemiology, growth rate and costs associated with heart failure must rely on a precise definition of what heart failure is (Table I).

Table I. Definitions of heart failure.

The focus of this article is a clinical syndrome which also includes patients with asymptomatic disease labeled NYHA class I heart failure, for example asymptomatic left ventricular systolic or diastolic dysfunction.[9] Many patients are not given a correct diagnosis, particularly those with mild to moderate heart failure in whom a diagnosis based solely on clinical findings is unreliable.[13] In the heart failure population, cardiac function must be objectively assessed by echocardiography.[14,15] Echocardiographic surveys of individuals within well-defined populations are needed.
Comprehensive reviews of the epidemiology and associated burden of heart failure have been published by McMurray et al[8] and Cowie et al.[7] The latter review gives a clear overview of the epidemiology of heart failure. Recently, McMurray and Stewart published a comprehensive update on the epidemiology, etiology, and prognosis of heart failure.[9]
One of the earliest articles on the epidemiology of heart failure came from the Framingham study.[6]
Analysis of 34 years of follow-up in the Framingham study provided clinically relevant insights into the prevalence, incidence, secular trends, prognosis, and modifiable risk factors of heart failure in a general population sample. Heart failure was found to be highly prevalent, affecting 1% of individuals in their fifties and rising progressively with age to afflict 10% of those in their eighties.[6] The annual incidence also increased with age, from approximately 0.2% in individuals aged 45 to 54 years, to 4% in men aged 85 to 94 years, the incidence approximately doubling with each decade of age.
In the Framingham study, hypertension and coronary artery disease were the predominant causes of heart failure and accounted for more than 80% of all clinical events. Factors reflecting deteriorating cardiac function were associated with a substantial increase in risk for overt heart failure. These include poor vital capacity (demonstrated as pulmonary vascular engorgement resulting from malfunction of the left ventricle), sinus tachycardia, and ECG evidence of left ventricular hypertrophy. The risk of heart failure tended to increase progressively with heart rate throughout the range observed in both sexes but more prominently in men than in women. At a rate above 85 bpm, the risk of heart failure in men was almost double that of individuals with lower heart rates at all blood pressure levels. Modifiable predisposing risk factors for heart failure included hypertension, impaired glucose tolerance, elevated total:HDL cholesterol ratio, obesity, and cigarette smoking. We believe that using simple clinical evaluations and laboratory tests, it is possible to identify high-risk candidates for heart failure early in its course, thus enabling preventive management before irreversible myocardial damage occurs.[6]
During the 1980s, the annual age-adjusted incidence of congestive heart failure among individuals aged 45 years was 7.2 cases per 1000 in men and 4.7 cases per 1000 in women, whereas the age-adjusted prevalence of overt heart failure was 24 per 1000 in men and 25 per 1000 in women. Despite improved treatments for ischemic heart disease and hypertension, the age-adjusted incidence of heart failure has declined by only 11% per calendar decade in men and by 17% per calendar decade in women during a 40-year period of observation. In the pre-b-blocker era, however, congestive heart failure remained highly lethal, with a median survival of only 1.7 years in men and 3.2 years in women, and a 5-year survival of 25% in men and 38% in women.[16]
The abovementioned article by McMurray and Stewart,[9] published in 2000, is the most recent on the epidemiology of heart failure. It demonstrates these data are principally available from five types of study:
• Cross-sectional and longitudinal follow-up surveys of well-defined populations: these have almost exclusively focused on individuals with clinical signs and symptoms indicative of chronic heart failure. Ongoing registries such as the IMPROVEMENT of HF,[3,4] the Swiss Heart Failure Registry,[5] and the future European Advanced Heart Failure Registry belong to this group. Most also include individuals from other types of study.
• Cross-sectional surveys of individuals who have been medically treated for signs and symptoms of heart failure within a well-defined region.
• Echocardiographic surveys of individuals within a well-defined population to determine the presence of left ventricular systolic dysfunction: one such survey is currently ongoing among an elderly population (age 70 to 80 years), organized by Ulf Dahlström in Sweden (personal communication).
• Nationwide studies of annual trends in heart failure-related hospitalization identified on the basis of diagnostic coding at discharge: the Euro Heart Failure Survey[17] is a major attempt to describe the quality of hospital care, both diagnostic and therapeutic, in patients with suspected or confirmed heart failure among member countries of the European Society of Cardiology (ESC). Patients will be interviewed subsequent to hospital discharge to assess their understanding of the condition, their side effects from and compliance with therapy, and their satisfaction with the management of their heart failure. The quality of management will be judged according to the recommendations contained in the ESC guidelines on the diagnosis and treatment of heart failure.[11 ,19] Outcome will be further assessed by repeated interviews in 6–12 months’ time. A further survey of heart failure in 2001/2002 is also planned. One article from Switzerland studied a group of heart failure patients referred in 1998 to a university hospital.[19] This study, however, was not nationwide.
• Comprehensive clinical registries collected in conjunction with clinical trials: these include a large proportion of individuals identified on the basis of having both impaired left ventricular systolic dysfunction and signs and symptoms of heart failure; the SOLVD and SPICE investigators set up this type of registry.[20,21]
In the USA, there are some 5 to 6 million heart failure patients comprising about 600,000 new cases per year. In Switzerland, there are some 150,000 heart failure cases[5] and equivalent to almost half the population of Zürich. The overall reported prevalence rate of heart failure in the UK, USA, and Sweden is between 3 and 20 per 1000 population and in the older age group ranges between 23 and 130 per 1000 population (Table II).[7–9],[22–31]

Table II. Reported prevalence of heart failure according to McMurray and Stewart.[9]

The reported incidence of heart failure was summarized in the literature as shown in Table III).[9]

Table III. Reported incidence of heart failure in the literature.[9]

Outlook
As already indicated, we can expect a remarkable increase in the prevalence of heart failure in the foreseeable future. It is difficult, however, to calculate a likely prognosis. Figure 1 depicts the incidence rate of congestive heart failure among Framingham heart study subjects according to gender and age.

Figure 1. Incidence rate of congestive heart failure among Framingham heart study subjects according to gender and age.[16]

Since the aging population is growing, we will have to confront a continuing increase in the numbers of heart failure patients at least in the Western industrialized countries.

Heart failure in the elderly
Heart failure readmission rates, especially in the elderly, are high.[40] Clinical trials have shown that the case fatality related to heart failure is high but can be significantly reduced by medical therapies such as ACE inhibitors and, more recently, ß-blockers. However, these studies have enrolled mainly middle-aged men and thus are unrepresentative of the general population of patients with heart failure, who tend to be elderly and distributed equally between the sexes. The prognosis of these older patients has been less well studied. MacIntyre et al[41] evaluated current survival and the impact of newer therapies such as ACE inhibitors and fatality rates over a 10-year period in a large unselected population of 66,547 patients referred to hospital. The study revealed that heart failure fatality is much higher in the general population than in clinical trials, especially in the elderly. Although survival has increased significantly over the last decade, there is still room for improvement.
Nurse-directed, multidisciplinary intervention has been shown to improve quality of life and reduce hospital use and medical costs in elderly patients with congestive heart failure.[42]

Impact on heart failure management
Only a small proportion of heart failure patients receive optimal treatment. There is a strong need to improve the care of patients with heart failure, encompassing the whole spectrum of patient management including diagnosis, medical treatment, and education of patients and relatives to increase their knowledge about heart failure and self-care. This could be achieved by dissemination of the specialized knowledge accumulated over many years in university-based heart failure centers. Regional heart failure centers should be established and staffed by specialist cardiologists. This strategy would enable the establishment of regional heart failure disease management programs and national cluster network systems. Since we are dealing with an epidemic, specially trained nurses must be employed in the future.[43] A number of countries have been using this successful comprehensive approach for many years.[13,50,44–48]

Costs
Cardiovascular disease accounts for approximately 40% of the annual mortality in the USA, and ischemic heart disease is the main cause of death in both men and women.[49] Within the context of this enormous public health problem, there are some both encouraging and discouraging trends. On the one hand, the death rate from myocardial infarction, the main cause of death within the general category of cardiovascular disease, has been declining over the last 20 years. Yet, as patients live longer with coronary artery disease, or as it develops later in life, the related problem of heart failure from ischemic cardiomyopathy or other causes has emerged as a health problem of epidemic proportions with major socioeconomic implications.[6,60] The high annual mortality, marked disability, and subsequent unemployability of subjects with heart failure are heavy burdens on society.
Heart failure consumes 1 to 2% of health care expenditure in a number of industrialized countries.[8] Figure 2 depicts the heart failure admissions rate per year in Western developed countries from 1978 to 1993. Figure 3 summarizes the costs of chronic heart failure compared with total health care expenditure in six different countries.

Figure 2. Heart failure admissions rate per year in Western developed countries from 1978 to 1993.[8]

Figure 3. The component of hospital costs contributing to total expenditure quoted in the local currency and (in brackets) the percentage of chronic heart failure expenditure attributable to hospitalization.

Unfortunately, statistics regarding the prevalence and social costs of heart failure are only estimates because of the complexity of data collection.
In Sweden, the yearly costs associated with heart failure are estimated to be around USD 260 million;[13] the hospital costs for heart failure account for up to 75% of total costs, whereas drugs only account for up to 8% of total costs.[52] We know that the readmission rate for patients with heart failure is quite high (29% to 47%) within 3 months of discharge from hospital.[40,53] Studies have shown that almost 50% of all readmissions might be preventable.[40,53] Information and self-education among heart failure patients are inadequate and as a result compliance is low.[54]
In the USA it is believed that at least USD 9 billion per year are spent caring for these patients and that about 300,000 people with heart failure die annually. These extrapolated numbers are taken from a 1993 publication.[50]
Many accepted cardiovascular interventions, such as revascularization for multivessel disease (USD 50,000 per year of life gained) or the use of statins for hypercholesterolemia in middle-aged men at high risk for cardiovascular events (USD 30,000 per year of life gained), are associated with moderate expense. By contrast, heart failure is one of the few conditions in which lives may be saved while significantly reducing costs. ACE inhibitors, b-blockers, and digoxin all appear to be cost-effective under widely differing sets of assumptions.[55] For example, calculations from the COPERNICUS study[56] revealed that if 1000 patients with heart failure similar to those in COPERNICUS were treated with carvedilol for 3 years, we would save about 200 lives (M. Packer, ESC 2000).
Being aware of the enormous impact of medical therapy of heart failure, there is no single strategy to prevent a global financial crisis in heart failure care. However, a set of recommendations has been proposed as a means to overcome major obstacles.[57–59] Even with managed care and government efforts to control growth, United States’ health spending per capita grew more rapidly in the 1990s than that in the average industrialized country.[60] Per capita health spending in 1997 ranged from a high of USD 3925 in the USA to a low of USD 260 in Turkey. Switzerland shares this problem as the country with the second-highest health care expenditure in the world (USD 2547 per capita). These data highlight the complexity of our modern health care system and show how economic calculations are difficult to make and can be biased. This has to be taken into account in discussions among specialist cardiologists, health care economists, and politicians.

REFERENCES

1: Am Heart J 1998 Jun;135(6 Pt 2 Su):S204-15