Denton Cooley, a renowned heart specialist who performed world's first artificial heart transplant in the US, has passed away at 96 years old.
Cooley, who was the founder of Texas Heart Institute, pioneered many techniques still used in cardiovascular surgery.
He and his groups also performed more than 118,000 open-heart operations.
Previous President George H W Bush said in an announcement: Barbara and I join the thousands of Houstonians, Americans, and admirers around the world who today are mourning the loss of a true giant, Denton Cooley.
"Denton's pioneering contributions to medicine are, of course, legend. But he also was a lifelong and leading citizen of Houston. All of us who call Houston home will always feel blessed to live in the city where Denton founded the Texas Heart Institute, making our hometown the global centre of cardiovascular research and technology," he said.
"You could even say it helps us sleep a little better at night. And of course Denton was a wonderful husband, father, and friend. He will be greatly missed, but we are happy he can rejoin his beloved Louise," he added.
His wife, Louise Goldsborough Thomas Cooley, died just a few weeks earlier on October 21 at the age of 92.
His family shared memories of a man who pioneered heart transplantation, developed an artificial heart and founded the Texas Heart Institute.
"He made sure he had time for each one of us, all of my children, all of their children, all of our grandchildren," Susan Cooley said.
"99 % of his patients were those that other doctors had given up on, and we said 'Denton, you can't do 18 operations a day and survive.' And he said, 'you tell me who I'm going to say no to,'" she said.