A new artificial heart which combines machinery with tissue from a cow will be implanted into humans for the first time.
The so-called 'bioprosthetic heart' is unique because it incorporates biological cells within its mechanism.
The synthetic organ uses a membrane made with tissue taken from material surrounding a cow's heart.
The organic membrane divides two chambers within the heart. By pumping fluid between the two chambers, via the membrane the heart is able to flow blood between the two sides.
The hope is that the machine would reduce patients' reliance on anti-coagulation medicine, and allow it to better adjust how blood flows during and after physical activity - using valves made with more cow tissue.
The heart, made by the French company Carmat has now gained approval from four cardiac centres in Europe and Saudi Arabia, and will be tested in patients for the first time before a potentially wider rollout.
Shares in Carmat rose 25% after the announcement, Reuters reported.
Reports suggest that the device would cost £128,000 each.
"Carmat expects to receive additional approvals in a near future, potentially in France and in other countries," said CEO Marcello Conviti in a statement.
Synthetic hearts are currently used as a "bridge" between a patient's natural heart failing and a donor organ being found.
But making a reliable heart replacement is enormously complicated, since the machine needs to be able to pump 35 million times a year - potentially for long periods of time.
Only one synthetic heart, made by American firm SynCardia, is currently approved for use in patients in Europe, the United States and Canada.