Secondary mitral regurgitation (MR) and heart failure are mutually dependent. Secondary MR occurs as a consequence of heart failure in patients with impaired left ventricular (LV) function, decreasing cardiac efficiency, accelerating a decline in contractility and worsening the already dismal prognosis of these patients. Advances in transcatheter techniques have now given promise to improved survival, outcomes, and quality of life for patients with advanced heart failure and secondary MR. Although transcatheter edge-to-edge repair is well established, transapical transcatheter mitral valve implantation (TMVI) may represent a more durable solution for correction of secondary MR without the need for cardiopulmonary bypass. Correction of MR, however, is thought to acutely increase LV afterload due to the elimination of low afterload regurgitant flow. In high-risk patients, this may cause acute decompensated heart failure. Off-pump TMVI on a beating heart poses a number of unique challenges, but also the opportunity to study invasive haemodynamic indices in high-risk heart failure patients for the first time. In the following discussion, we review the acute haemodynamic changes during off-pump TMVI in patients with heart failure in order to better guide optimal patient selection and management.