The problem of defining heart failure

Universal definition and classification of heart failure: a report of the Heart Failure Society of America, Heart Failure Association of the European Society of Cardiology, Japanese Heart Failure Society and Writing Committee of the Universal Definition of Heart Failure: Endorsed by the Canadian Heart Failure Society, Heart Failure Association of India, Cardiac Society of Australia and New Zealand, and Chinese Heart Failure Association

In this document, we propose a universal definition of heart failure (HF) as a clinical syndrome with symptoms and/or signs caused by a structural and/or functional cardiac abnormality and corroborated by elevated natriuretic peptide levels and/or objective evidence of pulmonary or systemic congestion. We also propose revised stages of HF as: At risk for HF (Stage A), Pre-HF (Stage B), Symptomatic HF (Stage C) and Advanced HF (Stage D). Finally, we propose a new and revised classification of HF according to left ventricular ejection fraction (LVEF). This includes HF with reduced ejection fraction (HFrEF): symptomatic HF with LVEF ≤40%; HF with mildly reduced ejection fraction (HFmrEF): symptomatic HF with LVEF 41-49%; HF with preserved ejection fraction (HFpEF): symptomatic HF with LVEF ≥50%; and HF with improved ejection fraction (HFimpEF): symptomatic HF with a baseline LVEF ≤40%, a ≥10 point increase from baseline LVEF, and a second measurement of LVEF > 40%.

Universal Definition and Classification of Heart Failure: A Report of the Heart Failure Society of America, Heart Failure Association of the European Society of Cardiology, Japanese Heart Failure Society and Writing Committee of the Universal Definition of Heart Failure

In this document, we propose a universal definition of heart failure (HF) as the following: HF is a clinical syndrome with symptoms and or signs caused by a structural and/or functional cardiac abnormality and corroborated by elevated natriuretic peptide levels and or objective evidence of pulmonary or systemic congestion. We propose revised stages of HF as follows. At-risk for HF (Stage A), for patients at risk for HF but without current or prior symptoms or signs of HF and without structural or biomarkers evidence of heart disease. Pre-HF (stage B), for patients without current or prior symptoms or signs of HF, but evidence of structural heart disease or abnormal cardiac function, or elevated natriuretic peptide levels. HF (Stage C), for patients with current or prior symptoms and/or signs of HF caused by a structural and/or functional cardiac abnormality. Advanced HF (Stage D), for patients with severe symptoms and/or signs of HF at rest, recurrent hospitalizations despite guideline-directed management and therapy (GDMT), refractory or intolerant to GDMT, requiring advanced therapies such as consideration for transplant, mechanical circulatory support, or palliative care. Finally, we propose a new and revised classification of HF according to left ventricular ejection fraction (LVEF). The classification includes HF with reduced EF (HFrEF): HF with an LVEF of ≤40%; HF with mildly reduced EF (HFmrEF): HF with an LVEF of 41% to 49%; HF with preserved EF (HFpEF): HF with an LVEF of ≥50%; and HF with improved EF (HFimpEF): HF with a baseline LVEF of ≤40%, a ≥10-point increase from baseline LVEF, and a second measurement of LVEF of >40%.

So many definitions of heart failure: are they all universally valid? A critical appraisal

Defining heart failure (HF) is a matter of finding the most appropriate words to formulate the definiens for HF that will be universally applicable in all specific circumstances pertaining to the nature of HF. Currently available definitions of HF contain ambiguities and notable deficiencies such that non-heart failure medical conditions can become mislabelled as heart failure. Principles of how best to formulate definitions have been employed to provide a guide on how to appraise published definitions of HF. A fundamental requirement of a good definition is that it should be universal, and by this criterion, we need to question the validity of a conventional dogma that a collection of clinical diagnostic features are equivalent to HF definitions. A long-standing deficiency in HF definitions is the inability to take into account the quantifiable extent of functional impairment of the heart. Other traditional misconceptions surrounding HF definitions have also been addressed. In line with Derek Gibson's proposal, we have rephrased William Harvey's description of the cardiac role in maintaining the circulation in terms of Newtonian physics and of the Law of Conservation of Energy to reach a more universal and less ambiguous definition of HF, with the objective of advancing the science of HF and the treatment of this distressing condition.