Dr. Cox trained in Cardiothoracic Surgery under Dr. David Sabiston at Duke University, where he served as an Assistant and then Associate Professor. He later became the first Evarts A. Graham Professor of Surgery and Chief of Cardiothoracic Surgery at Washington University School of Medicine and Barnes Hospital, a position he held for 14 years. He retired in 2000 as Chairman of Cardiothoracic Surgery at Georgetown University Medical Center and became Emeritus Professor at Washington University in 2006. Dr. Cox has held leadership roles, including President of the American Association for Thoracic Surgery, and is best known for developing the Cox-Maze Procedure, the gold standard for treating atrial fibrillation.