Cardiac disease is the leading cause of cell death globally, according to the World Health Organization. However, predicting cardiac arrhythmia and cardiac failure, understanding the pathological mechanisms underlying onset and progress, and devising new treatments for cardiac diseases remain challenging. Human induced pluripotent stem cells (hiPSCs) from patients could revolutionise the way we study human disease but, unfortunately, they still fall short in recapitulating complex cardiovascular diseases. We are addressing these challenges in Mini-HEART. We are building advanced three-dimensional cardiac microtissues or “mini-hearts” using different cardiac cell types that we derive from hiPSCs. We aim to 1) Capture signs of cardiac diseases that so far have been difficult to be identified with hiPSC-based models, in particular signs appearing in early adulthood; 2) Understand which of the many cell types present in the heart are responsible for triggering the disease; 3) Test new therapeutic strategies, such as gene editing, to alleviate the disease signs. Our work will create new opportunities for designing novel biomedical tools to capture cardiac disease traits in the laboratory and develop new therapeutic approaches for heart disease.