A proposal to standardize dyspnoea measurement in clinical trials of acute heart failure syndromes: the need for a uniform approach.

Dyspnoea is the most common presenting symptom amongst patients with acute heart failure syndromes (AHFS). It is distressing to patients and therefore an important target for treatment in clinical practice, clinical trials, and for regulatory approval of novel agents. Despite its importance as a treatment target, no consensus exists on how to assess dyspnoea in this setting. There is a considerable uncertainty about the reproducibility of the various instruments used to measure dyspnoea, their ability to reflect changes in symptoms and whether they accurately reflect the patient's experience. Little attempt has been made to ensure consistent implementation with respect to patients' posture during assessment or timing in relationship to therapy. There is also limited understanding of how rapidly and completely dyspnoea responds to standard therapy. A standardized method with which to assess dyspnoea is required for clinical trials of AHFS in order to ensure uniform collection of data on a key endpoint. We propose the Provocative Dyspnoea Assessment, a method of measurement that combines sequential dyspnoea provocation by positioning and walking with a dyspnoea self assessment using a five-point Likert scale, to yield a final Dyspnoea Severity Score. This proposed tool requires detailed validation but has face validity for the uniform assessment of dyspnoea.