A British man has entered the record books as the world's longest-surviving heart transplant patient.
John McCafferty, 71, was told he had five years to live when he underwent the life-saving operation at Harefield Hospital in Middlesex 31 years ago.
He has now surpassed the previous record of 30 years, 11 months and 10 days, set by American Tony Huesman, who died in 2009.
Mr McCafferty, from Newport Pagnell, Buckinghamshire, said he hoped his record would act as an "inspiration" to patients awaiting transplants.
He was presented with his Guinness World Record certificate at the hospital, where he continues to have treatment.
"At the time of my heart transplant I was told that I might expect to live for another five years if the procedure was a success," Mr McCafferty said.
"The idea that I would live to see my 70s was inconceivable. Yet here I am.
"I want this world record to be an inspiration to anyone awaiting a heart transplant and to those who, like me, have been fortunate enough to have had one. My advice is always to be hopeful, to look ahead with a positive mind, and, of course, to follow the expert medical advice."
Mr McCafferty received his new heart on October 20 1982 in a procedure carried out by world-renowned surgeon Sir Magdi Yacoub.
He had been diagnosed, aged 39, with dilated cardiomyopathy - one of the most common causes of heart failure.
It leads to scarring of the heart wall and damage to the muscle, which causes the heart to become weakened and enlarged, preventing it from pumping efficiently.
Following his operation, Mr McCafferty followed the advice of doctors and remained fit and healthy - travelling across the UK and Europe to compete in 11 Transplant Games.
"It was important to me to prove that life doesn't stop at transplantation and to have a fitness regime to follow," Mr McCafferty said.
"Most importantly, I wanted to promote organ donation at every opportunity.
"I will always be indebted to my donor and to a family who I have never met. They have given me a life with my family - one which I could never have had without their gift."
Andre Simon, director of transplantation at Royal Brompton and Harefield NHS Foundation Trust, said: "John's achievement is remarkable and shows just what can be gained through transplantation.
"The fact that he has become a world record holder should act as motivation to those awaiting life-saving transplants and to those who have received the gift of a new organ.
"John's long and active life post-transplant can be attributed to a combination of his determination to follow a healthy lifestyle and to his excellent ongoing medical care. And, of course, he has needed a little bit of luck along the way."
Mr McCafferty is public governor of Royal Brompton and Harefield NHS Foundation Trust and serves as secretary of the Harefield Re-beat Club, as well as a committee member of the Harefield Transplant Club.
McCafferty, a father of one and grandfather of one, lives with his wife Ann, 68.
The genetic heart condition he suffered also affected Mr McCafferty's nephew Steven Paterson, who had a successful heart transplant at Harefield Hospital in 1991 at the age of 12.