Medicina

Seminar

Heart failure
Henry Krum, William T Abraham

Despite advances in management of heart failure, the condition remains a major public-health issue, with high prevalence, poor clinical outcomes, and large health-care costs. Risk factors are well known and, thus, preventive strategies should have a positive effect on disease burden. Treatment of established systolic chronic heart failureincludes use of agents that block the renin-angiotensin-aldosterone and sympathetic nervous systems to prevent adverse remodelling, to reduce symptoms and prolong survival. Diuretics are used to achieve and maintain euvolaemia. Devices have a key role in management of advanced heart failure and include cardiac resynchronisation in patients with evidence of cardiac dyssynchrony and implantation ofa cardioverter defibrillator in individuals with low ejection fraction. Approaches for treatment of acute heart failure and heart failure with preserved ejection fraction are supported by little clinical evidence. Emerging strategies for heart failure management include individualisation of treatment, novel approaches to diagnosis and tracking of therapeutic response, pharmacological agents aimedat new targets, and cell-based and gene-based methods for cardiac regeneration.

Lancet 2009; 373: 941–55 Centre of Cardiovascular Research and Education in Therapeutics, School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC, Australia (Prof H Krum FRACP); and Division of Cardiovascular Medicine, Davis Heart and Lung Research Institute, Ohio State University,Columbus, OH, USA (Prof W T Abraham MD) Correspondence to: Prof Henry Krum, Centre of Cardiovascular Research and Education in Therapeutics, School of Public Health and Preventive Medicine, Monash University and Alfred Hospital, Melbourne, VIC 3004, Australia henry.krum@med.monash. edu.au

Introduction
Considerable advances have been made in management of heart failure over the past few decades. Inoutpatient-based clinical trials, mortality has more than halved in people with established systolic chronic heart failure; moreover, admissions have fallen and patients’ quality of life has risen. Nevertheless, heart failure remains a major publichealth issue, with high prevalence and poor outcomes. Management of this condition includes appropriate nonpharmacological strategies, use of drugs(particularly those that inhibit key activated neurohormonal systems), and implantation of devices in appropriate patients. Surgery and transplantation are also options for selected individuals with highly advanced disease. Despite the promise of new drugs, cell-based therapeutic approaches, and novel devices, a reduction of disease burden is likely to come from preventive strategies. The antecedents toheart failure are well known; enhanced diagnostic precision coupled with early intervention could lessen the burden of disease. In this Seminar we will review recent and emerging data for epidemiology and diagnosis and current and future management techniques to ameliorate heart failure.

Epidemiology
Heart failure is a clinical syndrome and, thus, definitions are imprecise. Most includereferences to typical symptoms and objective evidence of abnormal ventricular function.1 Estimates of heart failure prevalence and incidence vary greatly because of non-uniformity in the definition, absence of a gold-standard measure for the disorder, and paucity of adequate and true epidemiological surveys. Furthermore, such data are confined largely to developed countries, although heart failure seems tobe growing in developing nations.2 Prevalence of heart failure rises steeply with increasing decades of life, particularly from age 50 years;3 the condition is rare in individuals younger than this age. In a cross-sectional survey of residents of Olmsted County, MN, USA, older than 45 years, overall prevalence was 2·2%, falling to 0·7% in those aged 45–54 years and
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