Circular RNA (circRNA) has a closed-loop structure, and its 3' and 5' ends are 
directly covalently connected by reverse splicing, which is more stable than 
linear RNA. CircRNAs usually possess microRNA (miRNA) binding sites, which can 
bind miRNAs and inhibit miRNA function. Many studies have shown that circRNAs 
are involved in the processes of cell senescence, proliferation and apoptosis 
and a series of signalling pathways, playing an important role in the prevention 
and treatment of diseases. CircRNAs are potential biological diagnostic markers 
and therapeutic targets for cardiovascular diseases (CVDs). To identify 
biomarkers and potential effective therapeutic targets without toxicity for 
heart disease, we summarize the biogenesis, biology, characterization and 
functions of circRNAs in CVDs, hoping that this information will shed new light 
on the prevention and treatment of CVDs.