This study will help to quantify heart and kidney ketone uptake with or without an exogenous ketone salt in heart failure condition.~Participants will have 2 different cardiac MRI to perform:~Fasting with exogenous ketone salt supplement~Fasting with exogenous carbohydrate supplement
Does oral intake of exogenous ketone salt improve heart function measured by cardiac MRI in heart failure compared to oral intake of a carbohydrate placebo?