The Eph/ephrin signaling pathway is crucial for the correct development of the vasculature. Previous research has shown that it plays an essential role in the maintenance of the vasculature in the heart. The vasculature plays an important role in maintaining the oxygen and nutrients supply to the heart, and indeed, changes in the microvasculature structure and functional impairment have been associated with heart failure. In particular, the Eph/ephrin signaling pathway is vital for transporting fatty acids to the cardiomyocytes. We will study histological sections, fatty acid concentrations in plasma and finally perform single-cell-RNA-sequencing to describe novel vascular specific causative mutation of cardiac disease. It is of clinical relevance for two reasons. First, it would increase the diagnostic tools for cardiac disease and would help to stratify the patients. And secondly, it will open a new avenue for the research of potential therapeutic strategies of cardiac disease; the coronary vasculature and in particular, the Eph/ephrin signaling pathway.