Therapeutic potential of ketone bodies on exercise intolerance in heart failure: looking beyond the heart

Recent evidence suggests that ketone bodies have therapeutic potential in many cardiovascular diseases including heart failure (HF). Accordingly, this has led to multiple clinical trials that use ketone esters (KEs) to treat HF patients highlighting the importance of this ketone therapy. KEs, specifically ketone monoesters, are synthetic compounds which, when consumed, are de-esterified into two β-hydroxybutyrate (βOHB) molecules and increase the circulating βOHB concentration. While many studies have primarily focused on the cardiac benefits of ketone therapy in HF, ketones can have numerous favourable effects in other organs such as the vasculature and skeletal muscle. Importantly, vascular and skeletal muscle dysfunction are also heavily implicated in the reduced exercise tolerance, the hallmark feature in HF with reduced ejection fraction and preserved ejection fraction, suggesting that some of the benefits observed in HF in response to ketone therapy may involve these non-cardiac pathways. Thus, we review the evidence suggesting how ketone therapy may be beneficial in improving cardiovascular and skeletal muscle function in HF and identify various potential mechanisms that may be important in the beneficial non-cardiac effects of ketones in HF.