Mechano-energetic uncoupling in heart failure

Heart failure (HF) is a major global and life-threatening disease. Despite advances in therapies, the prevalence of HF is increasing owing to an ageing population and the pervasive pandemic of obesity and metabolic disorders, which have transformed the pathophysiology of HF. Changes in cardiac energy metabolism and the related energy deficit crucially contribute to the severity and type of HF. Furthermore, perturbations in excitation-contraction coupling, mitochondrial function and oxidative stress are characteristic features of HF. In this Review, we focus on the close interaction between cardiac mechanics and mitochondrial energetics, and decipher how this mechano-energetic coupling is disturbed in various acquired and hereditary forms of HF. In HF with reduced ejection fraction, defects in excitation-contraction coupling are key drivers of mechano-energetic uncoupling, whereas in HF with preserved ejection fraction, increased preload and afterload imposed by obesity, hypertension and age-dependent vascular stiffness increase mechanical workload, which is insufficiently matched by mitochondrial tricarboxylic acid cycle activity and ATP supply. In both scenarios, oxidative stress results from depletion of the antioxidative capacity and contributes to maladaptive cardiac remodelling and dysfunction. Several established and emerging treatments for HF target this mechano-energetic uncoupling, and a greater understanding of the underlying mechanisms will open new therapeutic opportunities to alleviate the burden of HF.