Houston ? When Dr. Michael E. DeBakey pushed forward with his groundbreaking research and maverick approach to medicine a half century ago, heart surgery was a medical marvel.

Today, in part because of his contributions, it routinely saves thousands of lives each day.

DeBakey, a world-famous cardiovascular surgeon who pioneered such now-common procedures as bypass surgery and invented a host of devices to help heart patients, died Friday night in Houston. He was 99.

According to a statement issued early Saturday by Baylor College of Medicine and Methodist Hospital, DeBakey died of “natural causes” shortly after arriving at the hospital. The hospital’s heart and vascular center bears his name.

DeBakey, whose career spanned more than 70 years, counted world leaders among his patients and helped turn Baylor from a provincial school into one of the nation’s great medical institutions.

“Dr. DeBakey’s reputation brought many people into this institution, and he treated them all: heads of state, entertainers, businessmen and presidents, as well as people with no titles and no means,” said Ron Girotto, president of The Methodist Hospital System.