World-renowned Houston heart surgeon Dr. Denton Cooley has died at the age of 96. His secretary confirmed he died at his home Friday morning.

Dr. Cooley pioneered many techniques in cardiovascular surgery and saved countless lives throughout his storied career. He performed the first human heart transplant in the United States in 1968.

“I was so impressed with the fact that you could actually replace this pump for the whole circulatory system,” Cooley said in a 2014 interview with TMC News. “The heart is one of the simplest organs in the body…not nearly as complex as the liver or the kidneys. The heart has only one function, which is to pump.”

In 1969, Dr. Cooley became the first heart surgeon to implant an artificial heart in a patient.

Dr. Cooley and his associates are credited with more than 118,000 open heart surgeries – more than any other group in the world, according to his bio on the Texas Heart Institute website.

He continued to work through his 90s.

“An old friend of mine just invited me to a birthday luncheon for his 100th birthday, and I told him he was sort of a role model for me. I’ve always thought life was like a marathon,” Cooley told TMC News. “You want to save some effort for the last hundred yards and have a little kick at the finish. And that’s what I would like to do.”

He was Chief of Cardiovascular Surgery at CHI St. Luke’s Health/Baylor St. Luke’s Medical Center and surgeon-in-chief emeritus at the Texas Heart Institute, which he founded in 1962.

“Dr. Cooley wanted to create an entity that would try, through research, to help people with cardiovascular disease,” said James T. Willerson, M.D., president of the Texas Heart Institute. “He and his colleagues at the time were doing most of the heart surgery for the entire United States, in adults and children. But he wanted to do more than the surgery, and he believed that he could establish a Texas Heart Institute that would be involved in research and education—the education of young doctors, in all facets of cardiovascular disease.”

Dr. Cooley was also a consultant in cardiovascular surgery at Texas Children's Hospital and a clinical professor of Surgery at The University of Texas Medical School at Houston.

“Dr. Cooley is probably the very best heart surgeon who has ever lived,” Willerson said in 2014. “He has great technical skills, enormous experience, the courage to tackle these things, and wonderful judgment about what needed to be done in individual patients.”

Cooley graduated from the University of Texas, where he played varsity basketball, in 1941 with highest honors. He earned his medical degree from Johns Hopkins University School of Medicine in 1944.

Cooley and his wife Louise were married nearly 70 years and had five daughters , 16 grandchildren and 17 great-grandchildren.

“From a personal standpoint, I have always believed that a man who is going to get ahead has to have a balanced life,” Cooley said in 2014. “I’ve tried, for most of my life, to give my first attention to my patients and to my practice, but also to my family..."

Louise Cooley, once the senior nurse at Johns Hospkins, died at the age of 92 on Oct. 24.

Former President George H.W. Bush issued the followed statement Friday:

"Barbara and I join the thousands of Houstonians, Americans, and admirers around the world who today are mourning the loss of a true giant, Dr. 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 center of cardiovascular research and technology. 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."