Denton Cooley implanted in 1969 the first total artificial heart in a human, using a device developed by DeBakey's team as a bridge to transplant. The patient survived 64 hours with the device before receiving the transplant, and died 32 hours later. The procedure demonstrated the technical viability of total mechanical cardiac support, but triggered one of the most intense ethical and institutional controversies in the history of cardiovascular surgery. In the tree it acts as the starting point of the mechanical replacement branch.