Genetic therapy can heal damage caused by a heart attack

In this study, published in Nature, the team of investigators from King’s College London delivered a small piece of genetic material, called microRNA-199, to the heart of pigs, after a myocardial infarction (heart attack) which resulted in the almost complete recovery of cardiac function one month later.

Myocardial infarction, caused by the sudden blocking of one of the cardiac coronary arteries, is the main cause of heart failure. It is a condition that now affects over 23 million people worldwide, according to the World Health Organisation.

At present, when a patient survives a heart attack, they are left with permanent structural damage to their heart through the formation of a scar, which can lead to heart failure in the future. By contrast, fish and salamander can regenerate the heart throughout life.

“It is a very exciting moment for the field,” said lead author Professor Mauro Giacca, from King’s College London. “After so many unsuccessful attempts at regenerating the heart using stem cells, which all have failed so far, for the first time we see real cardiac repair in a large animal.”

This is the first demonstration that cardiac regeneration can be achieved by administering an effective genetic drug that stimulates cardiac regeneration in a large animal, with heart anatomy and physiology like that of humans.

“It will take some time before we can proceed to clinical trials,” continued Professor Giacca. “We still need to learn how to administer the RNA as a synthetic molecule in large animals and then in patients, but we already know this works well in mice.”