Cribier was ready to test the device in humans, but his first patient could not be eligible for conventional surgical valve replacement, which is safe and highly effective: to test an unproven new procedure on such a patient would be to expose them to unnecessary risk.

In early 2002, he was introduced to a 57-year-old man who was, in surgical terms, a hopeless case. He had catastrophic aortic stenosis which had so weakened his heart that with each stroke it could pump less than a quarter of the normal volume of blood; in addition, the blood vessels of his extremities were ravaged by atherosclerosis, and he had chronic pancreatitis and lung cancer. Several surgeons had declined to operate on him, and his referral to Cribier’s clinic in Rouen was a final roll of the dice. An initial attempt to open the stenotic valve using a simple balloon catheter failed, and a week after this treatment Cribier recorded in his notes that his patient was near death, with his heart barely functioning. The man’s family agreed that an experimental treatment was preferable to none at all, and on 16 April he became the first person to receive a new aortic valve without open-heart surgery.

Over the next couple of days the patient’s condition improved dramatically: he was able to get out of bed, and the signs of heart failure began to retreat. But shortly afterwards complications arose, most seriously a deterioration in the condition of the blood vessels in his right leg, which had to be amputated 10 weeks later. Infection set in, and four months after the operation, he died.

He had not lived long – nobody expected him to – but the episode had proved the feasibility of the approach, with clear short-term benefit to the patient. When Cribier presented a video of the operation to colleagues they sat in stupefied silence, realising that they were watching something that would change the nature of heart surgery.