Shumway completed the first successful U.S. adult heart transplant in 1968.
He may be best known for continuing with transplant research as many others quit during the 1970s, discouraged that most recipients died soon after their operations because of organ rejection or infections.
Shumway stuck with it and built a large transplant research team at Stanford that found ways to overcome transplant rejection problems.
He developed tests that enabled the use of smaller doses of dangerous rejection drugs and was one of the first transplant surgeons to begin using the safer rejection drug cyclosporine.
Ultimately, Shumway dramatically improved survival rates for transplant recipients.