Executive Leadership
Meet our Dignity Health Chandler Regional Medical Center team.
Mark F. Slyter, DSc, FACHE
President & Chief Executive Officer
Mark F. Slyter is the President and CEO of Dignity Health’s Arizona East Valley market which includes Mercy Gilbert Medical Center and Chandler Regional Medical Center.
During Mark’s 25-year career, he has achieved progressive healthcare experience as the chief executive officer or hospital president in small, medium, and large hospitals then advancing to serve as the CEO in tertiary and academic health systems. He produces substantial improvements across a balanced scorecard of safety, quality, finance, value, growth and patient, employee and physician satisfaction. Mark rallies key stakeholders to embrace new approaches and achieve a culture of high reliability in patient-centered care.
Prior to joining Dignity Health, Mark was President and CEO of General Health System / Baton Rouge General, a three-hospital system with 686 beds, two regional-referral and academic-medical-center campuses, a rehabilitation facility, and clinics. During his tenure, Baton Rouge General Mid-City Hospital transformed into a post-acute specialty campus, improved operating margins, reduced costs, and achieved high patient-satisfaction and employee-engagement scores.
Mark was also president and chief executive officer at Mississippi Baptist Health Systems, in Jackson, Miss., where he enhanced operating margins and efficiencies while dramatically increasing patient satisfaction. He has led both start-up academic medical centers and established major teaching hospitals that annually trained more than 500 medical students, residents, fellows, nurses, technologists, and other healthcare professionals.
Brian Galle, MHA
Vice President, Operations
As Vice President of Operations, Brian Galle oversees a variety of clinical and support departments at both Chandler Regional Medical Center and Mercy Gilbert Medical Center.
Brian serves as the executive for major construction projects at both hospitals, including the Women and Children’s Pavilion, a unique partnership between Dignity Health and Phoenix Children’s Hospital on Mercy Gilbert’s campus, and the recently completed Tower D Expansion at Chandler Regional Medical Center.
Prior to his current role, Brian was the Chandler Regional Director of Radiology. During his tenure, he oversaw expansion of imaging services to support growing services in trauma, neurosurgery and high-risk obstetrics delivery. In addition, he worked to expand imaging capabilities and update current systems to the latest in new technology, adding 3T Digital MRI, advanced interventional radiology and fully digital x-ray imaging.
Brian got his start in health care in the US Army as a Radiologic Technologist (Radiology Specialist) and still holds his registry today. Upon conclusion of service, he worked first as a technologist and progressed through leadership positions. Brian has his bachelor's degree in management and organizational development from Fresno Pacific University and a master’s of health administration from the University of Phoenix.
Yagnesh Patel
Vice President, Medical Affairs
Dr. Yagnesh Patel is the Vice President of Medical Affairs for Mercy Gilbert Medical Center. In 2015, Dr. Patel joined the executive leadership team at Chandler Regional and Mercy Gilbert Medical Centers as Vice President of Medical Affairs. In this role, Dr. Patel is responsible for daily operations surrounding quality, risk, patient safety and medical management.
He has been associated with Dignity Health since 1996 when he joined the medical staff as an internist. Dr. Patel transitioned to hospital medicine in 1998 and has been a hospitalist at both Chandler Regional and Mercy Gilbert Medical Centers where he served as Chairman of the medicine and family practice departments and then medical staff president in 2014-2015.
Dr. Patel earned his medical degree from the University of Nairobi in Kenya and after practicing emergency medicine in Kenya, he immigrated to the United States in 1992. Dr. Patel completed his residency in internal medicine at the Catholic Medical Centers of Brooklyn and Queens, NY before moving to Arizona. He is board certified in internal medicine with a focused practice in hospital Medicine and hospice and palliative Medicine.
Jeff McBee, MHA, MBA
Chief Operations Officer
Jeff McBee is the Chief Operating Officer (COO) for Dignity Health Chandler East Valley, which includes Chandler Regional Medical Center and Mercy Gilbert Medical Center. As COO, he oversees daily operations for both East Valley hospitals and cardiovascular services forand both facilities.
Prior to his position with Dignity Health, Jeff served as Administrator of Rust Medical Center at Presbyterian Healthcare Services in New Mexico. He previously served in various leadership roles in hospital operations and supply chain at Maricopa Integrated Healthcare System, Phoenix; Parkland Hospital, Dallas, Tex., Duke University Health System, Durham, NC, and Guthrie Healthcare System in Sayre, Pa.
Jeff received his bachelor’s in psychology, master’s of health administration, and master’s of business administration from the University of Missouri-Columbia.
Jeff is a member of the American College of Healthcare Executives.
Roger Bies, MD, FACC, FSCAI
Chief Medical Officer
Dr. Roger Bies is a practicing Cardiologist serving as the Chief Medical Officer for Chandler Regional Medical Center and Mercy Gilbert Medical Center, collectively known as Dignity Health East Valley hospitals, since 2016.
Dr. Bies has been strategically involved in the advancement of quality and business efficiencies within the East Valley medical staff departments, in addition to overseeing contracting and negotiations, hospitalist programs, and in-house OB/GYN services programs. He works collaboratively with East Valley nursing leadership to align to physician training for optimal patient experience. Dr. Bies is also the Designated Institutional Officer for advancing 5 new ACGME residency training programs at Chandler Regional and Mercy Gilbert.
Prior to this role, Dr. Bies established and was the executive lead for Heart Health Organization, a group of 34 cardiologists and cardiovascular surgeons who provide co-management services to East Valley hospitals. He also established an Annual International training course in Cardiovascular Computed Tomography (CCTA), and has served on the certification board and exam development committee since 2011.
Dr. Bies moved to Arizona with his family in 1998, serving the Chandler community as an Interventional Cardiologist. He was the founder and first chairman for the cardiovascular department at Chandler Regional Medical Center and served as its lab director for 10 years.
Dr. Bies graduated with honors from University of Colorado, and completed his residency in internal medicine at University of Pittsburgh Medical Center. He completed his fellowship in cardiology at Baylor College of Medicine, Houston, which included an American Hospital Association/Bugher sponsored research fellowship at the Institute for Molecular Genetics.
Dr. Bies served as faculty and Assistant Cardiology Program Director at the University of Colorado HSC from 1993-1998 and has published over 50 peer reviewed articles, books, monographs, and abstracts in CV Medicine.
Eric Sorensen
Chief Financial Officer, Dignity Health East Valley
Eric Sorensen is the Chief Financial Officer for Dignity Health East Valley, which includes Chandler Regional Medical Center and Mercy Gilbert Medical Center. Eric is also the Interim CFO for Dignity Health in Arizona and Nevada, the Southwest Division of CommonSpirit Health.
Eric oversees the finance and decision support functions with a matrixed relationship with the corporate office for general accounting, payroll and accounts payable. He is also responsible for maintaining the relationship with Optum360 East Valley revenue cycle.
Eric received his Bachelor of Science in Health Care Administration and Master of Business Administration from the University of Arizona. He is also a Certified Public Accountant.
Maryann Bowersox, DNP, RN
Chief Nursing Officer
Maryann Bowersox is the Chief Nursing Executive for Dignity Health Chandler Regional Medical Center. She has been a Registered Nurse for more than 30 years and has spent the majority of her career at the bedside which enabling her to influence both her patients and nurses.
As Chief Nursing Executive, Bowersox provides leadership to achieve and exceed quality metrics and reduce serious safety events. She opened the East Valley Weight Loss Center and implemented the Dignity Health East Valley tumor boards.
Bowersox came to Arizona as a travel nurse with St. Joseph’s Hospital and Medical Center. She officially joined the Dignity Health team in 2002. Maryann began her nursing career as a nurse’s aide in Wilkes-Barre, Penn. After becoming a Registered Nurse and working in her Pennsylvania hometown, she then travelled throughout the United States working in various organizations as a nurse inTelemetry, Oncology, Bone Marrow Transplant and Rehabilitation areas.
Maryann obtained her bachelor’s in nursing from Bloomsburg University; master’s in nursing from Grand Canyon University, and doctor of nursing practice from Walden University.
She is a Professor of Practice in the Edson College of Nursing and Health Innovation, and a member of the Arizona Nurse Association of Executive Leadership and the American Nurses Association.
Mario Valadez, Jr., MDIV
Market Vice President, Mission Integration
JMario Valadez is the Market Vice President of Mission Integration for Dignity Health in Arizona’s eastern region which includes Arizona General Hospital-Mesa. Mario previously served as Senior Director of Mission Integration for Dignity Health’s East Valley hospitals. He has been with Dignity Health for 15 years. Mario’s inspiration comes from our founding legacy of the Sisters of Mercy and their rich heritage in faith.
He earned his master of divinity degree from Princeton Theological Seminary with an emphasis in pastoral counseling. His love for tradition and heritage was nourished in the seminary’s 200-year-old history. Early on, he began writing reflections and montages of his rich chaplain experiences, and found a deeper admiration for the things of God and how we connect with these “things”and each other.
Mario is the proud father of four children and husband to Sarah.
In his spare time, Mario enjoys square-foot gardening, cultivating his urban orchard and spending time with his wife and kids. He also enjoys traveling, hiking, restaurants and beaches.