Dr. Stephen Colvin, a heart surgeon whose innovative thinking made him an early pioneer of minimally invasive cardiac procedures, died suddenly on Saturday at 64.

As the founding chairman and a senior surgeon in the department of cardiothoracic surgery at NYU Medical Center, Colvin performed nearly 10,000 surgeries in his 30 years at NYU.

His death, confirmed by the hospital, followed a diagnosis of multiple myeloma, a cancer of the plasma cell, just more than a week ago. Colvin passed away within 48 hours of performing his last surgeon on Thursday.

Those who worked closely with him said Colvin’s determination was rooted in a belief that every problem has a solution. “That drove him to be very innovative and come up with new surgical techniques,” the chairman of cardiothoracic surgery at NYU, Dr. Aubrey Galloway, said. “Numerous times, he’d call me at 2 o’clock in the morning with a great surgical idea. He couldn’t wait until the next morning to tell me.”

Colvin was particularly adept at operating on children born with heart defects, and in 2001 he co-founded Project Kids Worldwide, a group dedicated to improving medical treatment for poor children.

Born in New York in 1943, Colvin earned his medical degree from the Albert Einstein School of Medicine. He did his internship and residency training at NYU Medical Center, and completed a fellowship at the National Heart and Lung Institute of the National Institutes of Health. He subsequently finished his training in cardiothoracic surgery at NYU, where he joined the faculty in 1978.

During his tenure, he served as chief of cardiac surgery and as founding chairman of the department of cardiothoracic surgery. In 1997, Colvin pioneered mitral valve repair, an open-heart procedure that treats narrowing or leakage of the mitral valve. With Dr. Galloway, he invented the Colvin-Galloway Future Band, a flexible ring to repair mitral valves. Colvin was also an early developer of minimally invasive heart surgery methods.

In addition to his accomplishments in the operating room, Colvin directed the residency program at NYU for 20 years, training more than 100 cardiac surgeons during that time.

A former student and an associate professor of cardiothoracic surgery at NYU, Dr. Greg Ribakove, recalled Colvin as a “bigger than life guy.”

In the early 1980s, Dr. Ribakove said he sought out Colvin as a mentor because the two shared research interests. Colvin not only facilitated a research opportunity at the National Institutes of Health, but also for two years paid the younger doctor’s salary out of his own pocket.

“He was a great teacher, a great surgeon,” Dr. Ribakove said. Years later, Dr. Ribakove assumed Colvin’s role as chief of cardiac surgery at Bellevue Hospital, where Colvin performed heart surgery for years without financial compensation.

Those who knew him described Colvin as an avid tuna fisherman who fished with the same intensity he displayed in the operating room.

Colvin was a fellow of the American College of Cardiology and the American College of Surgeons. He was a member of numerous professional organizations, including the Society of Thoracic Surgeons. Colvin leaves behind his wife, Helane, and their two young children, Sean and Mikaela, as well as two grown daughters from his first marriage, Laurel and Heather, a son-in-law, Andrew, and three grandchildren.