Expanding the clinical classification of heart failure: Inclusion of cardiac function during exercise

Despite recent advances in the pathophysiological understanding of heart failure with reduced (HFrEF) or preserved (HFpEF) ejection fraction, there remains an appreciable level of patients whose clinical severity is not optimally classified using traditional paradigms. Although exercise intolerance is a hallmark feature across HF, while also a key marker of patient prognosis that is not related to resting left ventricular ejection fraction, it is not currently routine to objectively assess the functional response of the cardiac system to exercise in the clinical setting. By contrast, accumulating patient-based evidence supports links between impaired exercise cardiac pumping capability and prognosis related to exercise intolerance in HF. Therefore, as a high-priority clinical need, this chapter focuses on discussing the science and real-world clinical value of routinely assessing exercise cardiac pumping capability in HF, which will advance the pathophysiological understanding of exercise intolerance in HF while also strengthening the traditional model used for the clinical classification of HF patients.