The researchers reported in the journal Science that these new vessels primarily develop from capillaries, the smallest blood vessels in the body, rather than from the strong, thick-walled arteries.

The prevailing view had been that collateral coronary vessels form when arterial connections widen in response to increased blood flow following a blockage.

Recent research has shown that these vessels can also form from scratch, but the mechanism behind this process has remained unclear.

Using genetically modified mice and genetic lineage-tracing tools to identify the origins of collateral blood vessel cells, the researchers found that most of these vessels originated from cells lining the capillaries.

They also found that using messenger RNA to deliver vascular endothelial growth factor A (VEGF-A), a protein involved in blood vessel growth, significantly enhanced the formation of functional collateral arteries and improved recovery from heart damage in mice.

The Chinese research team said the findings shed light on a molecular pathway that could potentially be harnessed to help repair heart problems.