The PRIMARY trial (NCT05051033), which compares mitral valve repair (MVr) to transcatheter-edge-to-edge-repair (TEER), offers a platform for conducting mechanistic studies to develop early insights into the pathophysiological processes by which mitral valve prolapse (MVP) can impact left ventricular (LV) myocardial structure and function, and, thereby, predispose to arrhythmias and sudden death. Such insights are key to identifying interventions to reduce the long-term sequelae of heart failure (HF) and arrhythmias, as well as delineate optimal therapeutic approaches for different patient sub-groups.