<qa>  What is the primary outcome of the trial?Design: A randomised double-blinded placebo-controlled clinical trial. Sample size: 40 patients, 20 in each group. The superior inter-study reproducibility results in considerably lower calculated sample sizes reductions of 55 to 93 required by cardiac MR compared with echocardiography to show clinically relevant changes. Power calculations show that only 30 patients are needed form our primary outcome, to allow for dropouts the investigators have chosen to include 40 patients. 