Heart failure (HF) is a major clinical and public health problem, with a prevalence of over 23 million worldwide. In 1997, it was singled out as an emerging epidemic (1, 2). HF refers to approximately 1-2% of the adult population in developed countries, with the prevalence rising to ≥ 10% among people in their seventies or older (3).

Early signs and symptoms of HF are usually non-specific and increase as the result of pathophysiological changes connected with age, such as oxidative stress, inflammation and other cardiovascular (CV) risk factors. The etiology of HF in older adults is considered multifactoral, and includes hypertension, diabetes, coronary artery disease, valvular disease, impaired renal function and chronic obstructive lung disease (3-5). HF is defined as a complex clinical syndrome that can result from any structural or functional cardiac disorder that impairs the ability of the ventricle to fill or to eject blood. As HF is considered a syndrome rather than a disease, its diagnosis relies on combined results of medical, laboratory and imaging examinations. The low physical activity, typical for many older individuals, can mask the development of dyspnea or fatigue. Fatigue at rest in the elderly may suggest depression rather than HF (1, 3, 4). Older people often attribute their HF symptoms to aging, delaying presentation until symptoms become more overt and severe. Cognitive and sensory impairments common in the elderly may additionally delay the diagnosis of HF (4). A clinical course of HF is usually characterized by periodic acute exacerbations. Acute decompensated HF is defined as a gradual or rapid change in heart failure signs and symptoms resulting in a need for urgent therapy. This definition comprises worsening chronic HF, new onset HF and advanced HF. Periodic exacerbations require intensification of treatment, most often in the hospital, and they are considered most frequent cause of hospitalization for people aged 65 years or older. Although HF incidence and prevalence increase disproportionately among the elderly aged ≥ 80 years, optimal management of this group of patients remains not firmly established, and standards of care developed for younger adults often fail to achieve beneficial outcomes for the very old HF population (1, 4).

There is no single test or procedure that can definitively confirm the diagnosis of HF. Similarly, there are many diagnostic criteria for HF to be used in clinical and population settings, and none of them is universally accepted (4). Several criteria were proposed to diagnose HF, e.g. the Framingham criteria, Boston criteria, Gothenburg criteria, and the European Society of Cardiology criteria. All of them rely on similar signs and symptoms, and combine data from the medical history, physical examination and chest X-ray (1). It was found that the specificity of the Framingham criteria and their predictive value were lower than those of the Boston score for definite HF, but they provided greater sensitivity to diagnose possible HF (6). The Boston criteria have been recommended over other criteria for older adults due to their construct validity and improved prediction of adverse outcomes (7).

Most clinical symptoms of heart failure overlap with manifestations of other conditions that often occur in elderly people. Symptoms such as exertional dyspnea, orthopnea, paroxysmal nocturnal dyspnea, fatigue and weakness have both poor sensitivity and specificity. Signs of fluid retention and sympathetic activation (tachycardia) as well as pulmonary venous hypertension found with chest X-ray can be supportive for the diagnosis (8).

The current classification of HF includes the parameters of left ventricular function. The left ventricular ejection fraction (EF) enables classifying HF as the one with preserved or reduced EF. Different thresholds have been suggested as a diagnostic value of decreased EF. The threshold of 55% was recommended by the American Society of Echocardiography, 50% was the result of Framingham Heart Study, while the Organized Program to Initiate Lifesaving Treatment for Hospitalized Patients with Heart Failure Registry, and the Acute Decompensated Heart Failure National Registry recommended the value of 40% as the cut-off point (9-11). For the very old adults, both HF with preserved EF (HFPEF) and HF with reduced EF (HFREF) are common, however occurrence of HFPEF increases more distinctly in relation to aging, especially in women (12). Several population-based studies, such as the Framingham Heart Study and the Olmsted County Study revealed that more than half of older HF patients demonstrated a form with preserved EF. The factors that particularly predispose older adults to HFPEF are arterial and myocardial stiffening. In elderly women augmented myocardial growth responses were observed that could additionally prone them to impaired diastolic physiology (13, 14).

Essential examinations that are considered to be helpful to diagnose HF include an electrocardiogram (ECG), chest X-ray and transthoracic echocardiography. The ECG is sensitive but non-specific test. Normal ECG, however, virtually rules out heart failure (15). A chest X-ray may demonstrate cardiac enlargement with or without pulmonary hemostasis, pulmonary venous hypertension, and/or interstitial pulmonary edema. The echocardiogram is the definitive test in the diagnosis of heart failure. This exam provides information on ventricular size and function as well as the prior occurrence of myocardial infarction such as areas of hypocontractility. All these examinations can be also useful in determining whether the underlying etiology is of ischemic or non-ischemic origin. Additionally, assessment of valvular structure and function, assessment of pulmonary pressure, and the presence or absence of pericardial disease may be useful in guiding therapy (4). Echocardiography-Doppler is considered the approach of choice to assess the diastolic function in routine practice. It was found, however, that the relationships between standard Doppler parameters and left ventricular diastolic pressures were uniformly poor. It was concluded that the diagnosis of diastolic HF could not be made on the basis of a single echo-Doppler parameter but, rather, all parameters had to be examined in concert and used in combination with clinical observations (16-18).