Researchers acknowledge the heart’s limited regenerative ability and are debating whether current data truly show regeneration through cell division, given a history of controversial findings and retracted papers.

A new wave of gene therapies aims to regenerate heart tissue and treat heart failure, with the first clinical trial focusing on growing new heart-muscle cells in humans and several other regenerative gene therapies in development.

The leading regenerative approach uses a virus to deliver RNA that inhibits the gene SAV1, effectively removing a brake on cell proliferation to spur cardiomyocyte division.

In animal models such as mice and pigs, this approach has driven cardiomyocytes to divide and improved heart function, including a notable 14% rise in ejection fraction in a pig heart-attack model, which supported regulatory backing for a human trial that started in June.

As heart failure becomes more common, current drugs mainly address symptoms rather than repairing the heart’s structure or function.

There is ongoing debate over whether observed cell division signals genuine regeneration or other cellular processes like multinucleation, and researchers emphasize the need for proper controls and standard-of-care comparisons to confirm efficacy.