Preamble
Guidelines summarize and evaluate all available evidence at the time of the writing process, on a particular issue with the aim of assisting health professionals in selecting the best management strategies for an individual patient, with a given condition, taking into account the impact on outcome, as well asthe risk-benefit-ratio of particular diag-nostic or therapeutic means. Guidelines and recommendations should help the health professionals to make decisions in their daily practice. However, the final decisions concerning an individual patient must be made by the responsible health professional(s) in consultation with the patient and caregiver as appropriate. A great number of Guidelines have been issued in recent years by the European Society of Cardiology (ESC) as well as by other soci-eties and organisations. Because of the impact on clinical practice, quality criteria for the development of guidelines have been estab-lished in order to make all decisions transparent to the user. The recommendations for formulating and issuing ESC Guidelines can be found on the ESC Web Site (http://www.escardio.org/guidelines-surveys/esc-guidelines/about/Pages/rules-writing.aspx). ESC Guide-lines represent the official position of the ESC on a given topic and are regularly updated. Members of this Task Force wereselected by the ESC to represent professionals involved with the medical care of patients with this pathology. Selected experts in the field undertook a comprehensive review of the published evidence for management (including diagno-sis, treatment, prevention and rehabilitation) of a given condition according to ESC Committee for Practice Guidelines (CPG) policy. A critical evaluation of diagnostic and therapeutic procedures was performed including assessment of the risk-benefit-ratio. Estimates of expected health outcomes for larger populations were included, where data exist. The level of evidence and the strength of recom-mendation of particular management options were weighed and graded according to predefined scales, as outlined in Tables 1 and 2. The experts of the writing and reviewing panels filled in declara-tions of interest forms which might be perceived as real or potentia.