Executive Bios


Donald H. Wilkerson, FACHE

Chief Executive Officer

St. David’s Medical Center

In July 2011, Don Wilkerson was named CEO of St. David’s Medical Center, which comprises four of the seven member hospitals of St. David’s HealthCare, including St. David’s Hospital, St. David’s Rehabilitation Hospital, St. David’s Georgetown Hospital and Heart Hospital of Austin. He came to St. David’s Medical Center after serving for 13 years as CEO of St. David’s North Austin Medical Center. Prior to moving to Austin, Wilkerson served as CEO of hospitals in Tennessee and Kentucky, and as an executive officer of hospitals in Virginia and Arkansas. He has been associated with HCA for 31 years.

While at St. David’s North Austin Medical Center, Wilkerson oversaw significant hospital growth with hospital bed capacity increasing from 128 beds to its licensed capacity of 332 beds with the completion of an $82-million expansion project in April 2009.

Wilkerson is active in the community having previously served as chairman of Discover Austin and as a member of the United Way Capitol Area Campaign Cabinet. He is currently a member of the board of directors of the American Cancer Society, Central Texas Division. Professionally, Wilkerson recently served as a member of the Texas Hospital Association Council on Policy Development. He is also a Fellow in the American College of HealthCare Executives and is certified in HealthCare Management.

Wilkerson has a Master of Science degree in HealthCare Administration from Trinity University and a Bachelor of Science in Business Administration degree from the University of Arkansas.


David Shimp, FACHE

Chief Operating Officer

St. David’s Medical Center

R. David Shimp, FACHE, was named chief operating officer of St. David’s Medical Center in January 2013.

Before joining St. David’s Medical Center, Shimp served in various roles at University of Oklahoma (OU) Medical Center in Oklahoma City, Okla., ultimately serving as the chief operating officer. In this role, he was responsible for leading a variety of programs and service lines at the 798-bed acute care academic medical center, including the Solid Organ Transplant Program, cardiovascular and oncology service lines, the Sleep Disorders Center, respiratory therapy and rehabilitation.

Prior to his work with OU Medical Center, Shimp served in a variety of roles, including associate administrator at Rose Medical Center in Denver, Colo., a 422-bed acute care medical center. OU Medical Center and Rose Medical Center are both part of the HCA (Hospital Corporation of America), St. David’s HealthCare’s parent organization.

Additionally, Shimp served as a systems analyst and administrative intern at Bon Secours Richmond Health System, a research intern at M.D. Anderson Cancer Center in Houston, Texas and a Michael E. DeBakey surgical intern at Baylor College of Medicine in Houston.

He earned his Master of Health Administration from Virginia Commonwealth University in Richmond, Va. He received his Bachelor of Arts degree in leadership studies with a minor in biology from the University of Richmond.

Shimp is a fellow of the American College of HealthCare Executives. He was also a member of the LifeShare Organ Procurement Organization Board of Directors and has served on the Executive Leadership Council of the American Heart Association. Shimp has also served as a volunteer for the Children’s Hospital Foundation, Medical Business District Board, United Way and Habitat for Humanity, among other organizations.


John R. Marietta, MD

Chief Medical Officer - Vice President of Medical Affairs

St. David’s Medical Center

Dr. Marietta currently serves as chief medical officer and vice president of medical affairs for St. David’s Medical Center. Before joining St. David’s HealthCare in 2004, Dr. Marietta, a General Internist, had an active outpatient and inpatient medical practice with Austin Diagnostic Clinic for 22 years and served as a General Internist for the Central Texas Veterans Health Care System from 2002 to 2004. Since 2002, he has served as a hospitalist for Hospital Internists of Austin.

Marietta received a bachelor’s degree with honors from the University of Texas, and his Doctor of Medicine from Baylor College of Medicine in Houston. His internship and residency in Internal Medicine was performed at Central Texas Medical Foundation in Austin, where he served as Chief Resident Internal Medicine in 1980.

Marietta served on various committees and boards throughout his career with Austin Diagnostic Clinic, the Central Texas Veterans Health Care system and St. David’s HealthCare. He is a member of the Travis County Medical Society, the Texas Medical Association, the Texas Club of Internists and the Austin Society of Internal Medicine.

He recently received the honor of being named a “Best Doctor” by Austin Monthly and a “Texas Super Doc” by Texas Monthly.

Julie Perez - Chief Financial Officer

Julie Perez

Chief Financial Officer

St. David’s Medical Center

As chief financial officer, Julie Perez oversees the financial operations of St. David’s Medical Center, which includes the campuses of Heart Hospital of Austin and St. David’s Georgetown Hospital, as well as St. David’s Rehabilitation Hospital.

Previously, Perez served as the market chief financial officer for Las Palmas Del Sol Healthcare in El Paso. In this position, she was accountable for the strategic planning, development and leadership of the hospital’s finances. Prior to her work at Las Palmas Del Sol Healthcare, Perez managed finances for Security Capital Group in El Paso, as well as Texas Tech University and Ronal P. Lentz, Certified Public Accountant (CPA) in Lubbock.

Perez earned her Bachelor of Business Administration in accounting, as well as her CPA license, from Angelo State University in San Angelo, where she graduated summa cum laude. She is a member of the Texas Society of Certified Public Accountants and the Healthcare Finance Management Association, and has served as the treasurer for the American Red Cross (El Paso chapter) and St. Clement’s Parish School, as well as the finance chairman of Western Hills United Methodist Church. Perez is also a graduate of Leadership El Paso, and she has served as a volunteer for various events, including Christmas in April, Juvenile Diabetes Association, American Heart Association and United Way.

Sheila Fata

​Sheila Fata

Chief ​Nursing Officer

St. David’s Medical Center

Sheila Fata was named chief nursing officer of St. David’s Medical Center in June 2015. Before joining St. David’s Medical Center, Fata served as vice president of operations and chief nursing officer at Houston Methodist Willowbrook Hospital, a 277-bed tertiary care facility. Her responsibilities included line authority for all nursing and clinical operations, with supervision of more than 1,100 employees. During her tenure there, Fata provided clinical oversight for a $250-million facility expansion, and she facilitated the onboarding of more than 400 clinical staff. She also initiated multiple new inpatient service lines, including cardiovascular surgery, neurosurgery, bariatric surgery, robotic surgery and pediatrics, among others.

Texas Nurses Association District 9 named Fata Outstanding Nurse for 2014. Houston Methodist Willowbrook Hospital attained Magnet recognition by the American Nurses Credentialing Center under her leadership.

Prior to her role with Houston Methodist Willowbrook Hospital, Fata held a variety of executive and managerial roles at Memorial Hermann Healthcare System in Houston; CHRISTUS St. Catherine Hospital in Katy; Park Plaza Hospital in Houston; MD Anderson Cancer Center, also in Houston; and at Whittaker Health Corporation of America in Tabuk, Saudi Arabia.

Fata earned her Bachelor of Science degree in nursing from The University of Texas Health Science Center in San Antonio, and she went on to earn her Master of Business Administration degree from Our Lady of the Lake University in San Antonio.

Fata is a member of the American Organization of Nurse Executives, Texas Organization of Nurse Executives, American College of Healthcare Executives, American Nurses Association and the Texas Nurses Association.

Esther Chung – Assistant Administrator

Kyle Landry – Assistant Administrator

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