The classification of heart failure predominantly relies on a single parameter, namely left ventricular ejection fraction (LVEF) – a measure of the left ventricle’s ability to contract. Until now, the clinical diagnosis and management of heart failure as well as basic physiological research have classified heart failure using LVEF cut-offs.
The use of such cut-offs suggests that LVEF-based heart failure categories have distinct pathophysiologies, whereas the individual patient has many other characteristics determining their disease phenotype. Enrolling heart failure patients for clinical trials based on their LVEF can therefore be problematic. Given that LVEF values can also change over time, this can also lead to patient misclassification and inappropriate treatment. For this reason, a clinical review published in the European Heart Journal’s “Controversies in cardiovascular medicine” section now challenges the current basis for classifying heart failure according to LVEF only.
Wide spectrum of heart failure phenotypes
Triposkiadis and the 41 other researchers who authored the paper present a consensus opinion. They use pathophysiological reasoning to argue that heart failure should be considered as a syndrome with a wide spectrum of overlapping phenotypes. Individual patients should be treated according to their initial disease triggers, their genetic, clinical and sociodemographic background, and the treatment available. As heart failure progresses, the patient’s functional and structural parameters also change, with levels simply differing – or overlapping – between individual patients. These various parameters cannot be used to define distinct heart failure subpopulations.
In their review, the authors provide evidence from literature for the serious limitations of using LVEF to classify heart failure patients, including imprecise physiological implications, and large variability depending on the measurement modality. However, they also describe the many epidemiological, clinical and pathophysiological characteristics shared by patients with heart failure, regardless of LVEF. They suggest that recognizing heart failure as a syndrome on a continuous spectrum will lead to a new means of stratifying the disease – aided by new technologies and scientific insights – which will also shape the design of future clinical trials.
Original article: Eur Heart J. 2019; 00, 1 – 11.
Author: Sally Hill