The present invention associates multiple circular (circRNA) with key functions of endothelial cells. The present invention provides circRNA transcripts that are correlated with cardiovascular diseases, in particular acute myocardial infarction. The circRNA of the invention therefore serve as biomarkers in the diagnosis of cardiovascular disorders. The invention provides the new nucleic acid molecules as well as diagnostic kits and compositions comprising the nucleic acids. Modulation of the expression of the circRNA of the invention further leads to endothelial cell sprouting, and therefore is applied as a treatment for cardiovascular diseases or pathological angiogenesis. The invention provides therapeutic agents modulating circRNA expression or function.
