Current Cardiology Reviews - Volume 9, Issue 2, 2013

Heart failure (HF) is a major cause of morbidity and mortality in high income countries. Shortage of population based HF studies from Low and Middle Income countries (LMIC) make global prevalence estimates difficult. In this editorial we discuss the possibility of generating HF data in LMICs by initiating HF surveillance systems integrated into the existing health surveillance system.

South Asia (SA) is both the most populous and the most densely populated geographical region in the world. The countries in this region are undergoing epidemiological transition and are facing the double burden of infectious and non-communicable diseases. Heart failure (HF) is a major and increasing burden all over the world. In this review, we discuss the epidemiology of HF in SA today and its impact in the health system of the countries in the region. There are no reliable estimates of incidence and prevalence of HF (heart failure) from this region. The prevalence of HF which is predominantly a disease of the elderly is likely to rise in this region due to the growing age of the population. Patients admitted with HF in the SA region are relatively younger than their western counterparts. The etiology of HF in this region is also different from the western world. Untreated congenital heart disease and rheumatic heart disease still contribute significantly to the burden of HF in this region. Due to epidemiological transition, the prevalence of hypertension, diabetes mellitus, obesity and smoking is on the rise in this region. This is likely to escalate the prevalence of HF in South Asia. We also discuss potential developments in the field of HF management likely to occur in the nations in South Asia. Finally, we discuss the interventions for prevention of HF in this region.

Heart failure (HF) carries a major burden of disease in East Asia, with high associated risk of mortality and morbidity. In recent decades, the epidemiology of HF has changed with social and economical development in East Asia. The burden of HF is still severe in East Asia. The prevalence of HF ranges from 1.3% to 6.7% throughout the region. As aetiological factors, ischaemic heart disease has increased and valvular disease reduced in most East Asian countries. Diuretics are the most commonly used drugs (51.0%-97%), followed by renin-angiotensin system (RAS) inhibitors (59%-77%), with angiotensin-converting enzyme inhibitors, ACEI, (32%-52%) and has angiotensin-2 receptor blockers, ARBs (31%-44%) in similar proportions. Betablocker use has also increased in recent years. Total mortality from HF ranges from 2% to 9% in China, Taiwan, Singapore, Thailand, and Japan. Age>65 years, diabetes mellitus, anaemia, renal dysfunction and atrial fibrillation (AF) are associated with adverse outcome. More prospective, region-specific data are still required, particularly regarding new drug therapies such as eplerenone and ivabradine.

Heart failure poses an increasing problem for global healthcare systems. The epidemiological data which has been accrued over the last thirty years has predominantly been accumulated from experience within North America and Europe. Initial large cohort, prospective longitudinal studies produced the first publications; however latterly the focus has shifted onto epidemiological data governing hospitalisation and mortality. The emphasis behind this shift has been the resource implications with regards to repetitive, costly and prolonged hospitalisation. The European experience in heart failure, though similar to North America has recently demonstrated differences in hospitalisation which may underlie the differences between healthcare system configuration. Heart failure however remains an increasing global problem and the endpoint of a variety of cardiovascular diseases. Allied with the fact of increasingly elderly populations and prior data demonstrating a steep rise in prevalent cases within more elderly populations, it is likely that the increasing burden of disease will continue to pose challenges for modern healthcare. Despite the predicted increase in the number of patients affected by heart failure, over the last thirty years, a clear management algorithm has evolved for the use of pharmacotherapies (neuro-hormonal antagonists), device based therapies (Implantable Cardioverting Defibrillator (ICD) and Cardiac Resynchronisation Therapy (CRT)) and mechanical therapies including left ventricular assist devices and cardiac transplantation. Though the management of such patients has been clearly delineated in national and international guidelines, the underuse of all available and appropriate therapies remains a significant problem. When comparing various epidemiological studies from different settings and timepoints, it should be remembered that rates of prevalence and incidence may vary depending upon the definition used, methods of accumulating information (with the possibility of bias) and the chosen cut point of defining left ventricular systolic dysfunction (LVSD).

Heart failure is a major health problem that affects patients and healthcare systems worldwide. Within the continent of North America, differences in economic development, genetic susceptibility, cultural practices, and trends in risk factors and treatment all contribute to both inter-continental and within-continent differences in heart failure. The United States and Canada represent industrialized countries with similar culture, geography, and advanced economies and infrastructure. During the epidemiologic transition from rural to industrial in countries such as the United States and Canada, nutritional deficiencies and infectious diseases made way for degenerative diseases such as cardiovascular diseases, cancer, overweight/obesity, and diabetes. This in turn has resulted in an increase in heart failure incidence in these countries, especially as overall life expectancy increases. Mexico, on the other hand, has a less developed economy and infrastructure, and has a wide distribution in the level of urbanization as it becomes more industrialized. Mexico is under a period of epidemiologic transition and the etiology and incidence of heart failure is rapidly changing. Ethnic differences within the populations of the United States and Canada highlight the changing demographics of each country as well as potential disparities in heart failure care. Heart failure with preserved ejection fraction makes up approximately half of all hospital admissions throughout North America; however, important differences in demographics and etiology exist between countries. Similarly, acute heart failure etiology, severity, and management differ between countries in North America. The overall economic burden of heart failure continues to be large and growing worldwide, with each country managing this burden differently. Understanding the inter-and within-continental differences may help improve understanding of the heart failure epidemic, and may aid healthcare systems in delivering better heart failure prevention and treatment.

Continued assessment of temporal trends in mortality and epidemiology of specific heart failure in South America is needed to provide a scientific basis for rational allocation of the limited health care resources, and strategies to reduce risk and predict the future burden of heart failure. The epidemiology of heart failure in South America was reviewed. Heart failure is the main cause of hospitalization based on available data from approximately 50% of the South American population. The main etiologies of heart failure are ischemic, idiopathic dilated cardiomyopathy, valvular, hypertensive and chagasic etiologies. In endemic areas, Chagas heart disease may be responsible by 41% of the HF cases. Also, heart failure presents high mortality especially in patients with Chagas etiology. Heart failure and etiologies associated with heart failure may be responsible for 6.3% of causes of deaths. Rheumatic fever is the leading cause of valvular heart disease. However, a tendency to reduction of HF mortality due to Chagas heart disease from 1985 to 2006, and reduction in mortality due to HF from 1999 to 2005 were observed in selected states in Brazil. The findings have important public health implications because the allocation of health care resources, and strategies to reduce risk of heart failure should also consider the control of neglected Chagas disease and rheumatic fever in South American countries.

The heart failure syndrome has been recognized as a significant contributor to cardiovascular disease burden in sub-Saharan African for many decades. Seminal knowledge regarding heart failure in the region came from case reports and case series of the early 20th century which identified infectious, nutritional and idiopathic causes as the most common. With increasing urbanization, changes in lifestyle habits, and ageing of the population, the spectrum of causes of HF has also expanded resulting in a significant burden of both communicable and non-communicable etiologies. Heart failure in sub-Saharan Africa is notable for the range of etiologies that concurrently exist as well as the healthcare environment marked by limited resources, weak national healthcare systems and a paucity of national level data on disease trends. With the recent publication of the first and largest multinational prospective registry of acute heart failure in sub-Saharan Africa, it is timely to review the state of knowledge to date and describe the myriad forms of heart failure in the region. This review discusses several forms of heart failure that are common in sub-Saharan Africa (e.g., rheumatic heart disease, hypertensive heart disease, pericardial disease, various dilated cardiomyopathies, HIV cardiomyopathy, hypertrophic cardiomyopathy, endomyocardial fibrosis, ischemic heart disease, cor pulmonale) and presents each form with regard to epidemiology, natural history, clinical characteristics, diagnostic considerations and therapies. Areas and approaches to fill the remaining gaps in knowledge are also offered herein highlighting the need for research that is driven by regional disease burden and needs.

The clinical syndrome of heart failure is the final pathway for a myriad of diseases that affect the heart, and is a leading and growing cause of morbidity and mortality worldwide. Evidence-based guidelines have provided clinicians with valuable data for better applying diagnostic and therapeutic tools, particularly the overwhelming new imaging technology and other, often expensive, therapies and devices, in heart failure patients. In the Middle East, progress has recently been made with the development of regional and multi-centre registries to evaluate the quality of care for patients with heart failure. A new heart function clinic recently began operation and has clearly resulted in a reduced readmission rate for heart failure patients. Many Middle Eastern countries have observed increases in the prevalence of the risk factors for the development of heart failure, including diabetes mellitus, obesity, and hypertension, with heart failure in the Middle Eastern population developing earlier than it is in their Western counterparts by at least 10 years. The earlier onset of disease is the result of the earlier onset of coronary artery disease, highlighting the need for Middle Eastern countries to establish prevention programs across all age groups. The health systems across the Middle East need to be modified in order to provide improved evidence-based medical care. Existing registries also need to be expanded to include long-term survey data, and additional funding for heart failure research is warranted.