Frailty is a geriatric syndrome which relies on the reduction of multisystem reserve capacity, whereas pre-frailty is a condition predisposing and preceding the frailty state. Frail people have a lower potential to respond to external stressors and various life incidents as well as they present a weak prognosis particularly in cardiovascular diseases. However, frailty is not only a set of physical deficits, but it also concerns psychological and social dimensions of human functioning. Hence, an approach to frailty should be multidimensional because such a concept more adequately reflects a functional degradation in the elderly. Frailty is usually associated with the impaired condition of circulatory system, and therefore, an identification of subclinical cardiovascular abnormalities which are associated with frailty is paramount in a context of frailty prevention and treatment. In this study, a comprehensive echocardiography will investigate cardiac function with a particular attention to features which typically change with age, like flow and diastolic parameters, as well as chambers sizes. Specifically, the impact of the impaired diastolic filling pattern on the frailty development will be thoroughly investigated. Another potential mechanism which may predispose to frailty is a dysfunction of the autonomic nervous system (ANS) - especially, its cardiac branch. ANS plays a crucial role in the response to internal or external stressors such as diseases and activities of daily living, and it plays a pivotal role in the homeostasis. Since frail people present a progressive homeostatic dysregulation, it is possible that the impairment in the cardiac ANS may maintain or accelerate the frailty process. In the present study, both tonic and reflex activities of the cardiac ANS will be explored with Finapres device (Finapres Medical Systems B.V., Amsterdam, the Netherlands) which is a gold standard for non-invasive continuous blood pressure monitoring and also allows ECG and respiratory signals recording. The study participants will also undergo routine medical examination, standard 12-lead electrocardiography, and measurements of body mass index and ankle-brachial index - the latter will reflect the degree of lower extremity arterial disease. A cognitive function and a psychological condition will be evaluated with the Mini-Mental State Examination (MMSE) and the Geriatric Depression Scale, respectively. A nutrition status will be checked with the Mini Nutritional Assessment (MNA). The Activities of Daily Living (ADL) and Instrumental Activities of Daily Living (IADL) will be assessed with dedicated scales. A risk of fall will be judged with the questionnaire concerning the falls history and by examining a postural stability on a force plate (AccuSway, AMTI, Watertown, MA, USA). The study group will comprise community dwelling elderly individuals over the age of 65 years who get around by themselves. The exclusion criteria include: institutionalization, inability to move around, and terminal diseases with an anticipated survival of less than 1 year. After 2 and 5 years, the participants will be re-examined for their frailty and independence status, and in addition, their life status will be checked with national identification numbers by using the National Health Found registration system. Sample size calculation indicates that the minimum sample size to investigate frailty development should equal 994 subjects (1% margin of error and 95% confidence interval), however, assuming 10% loss in follow-up, the final sample size is 1093 subjects.

The primary endpoints of this study are: (i) to identify risk factors associated with multidimensional and physical frailty and pre-frailty in community dwelling elderly people over the age of 65 years; (ii) to find determinants for the development of different types of frailty in a prospective observation. The secondary endpoints are: (i) to explore the impact of various modes of frailty and other clinical factors on the elderly people mortality; (ii) to identify predictors for frailty development, disability or mortality as a composite endpoint; (iii) to explore the rate and determinants of a frailty status transition to a more robust status; (iv) to establish the prevalence of multidimensional frailty, and physical frailty and pre-frailty in elderly people in Polish community; (v) to determine a concordance/discordance between physical and multidimensional frailty.