Meet Our Executives

Kevin A. Roberts, FACHE​
President/CEO

Kevin's passion in health care is for quality and communication. He is committed to ensuring that every interaction we have with patients, families and our communities conveys the high-quality experience that is required of us. He is guided by the idea that there are very few limits to what we can do if we let God help us.

Kevin has worked in Adventist Health facilities for many years, as well as for-profit and not-for-profit systems in Hawaii, Idaho, Utah and Sacramento. He received his nursing degree from Pacific Union College and holds a masters degree in Public/Health Services Administration from the University of San Francisco.



Irene Bourdon​
President, Healthcare Foundation

As president of the Healthcare Foundation, Irene oversees fundraising and philanthropy at GAMC. She held several executive positions with Citrus Valley Health Partners, a health system in the East San Gabriel Valley and Riverside Community Hospital, a 445-bed acute care hospital in the Inland Empire. In addition to philanthropy, Irene has extensive experience in strategic planning, marketing and public relations, specifically in health care.

Irene has been involved in many community organizations, including serving on the Public Affairs Committee of the Hospital Association of Southern California, the Board of Directors for the Greater Riverside Chambers of Commerce and many service and civic organizations. She holds a bachelor’s degree from California State University, Long Beach and a master’s degree in public health from California State University, Northridge.



Warren Tetz

Senior Vice President/COO

Warren sees his role at Glendale Adventist Medical Center as a supporting one, helping to remove barriers so that hospital staff can care for patients and their families more efficiently. Additionally, he works directly with various departments as well as the hospital's multi-million dollar construction project.

Warren earned a degree in management from Loma Linda University and has worked in Adventist Health for more than 30 years. He started his career at White Memorial Medical Center in east LA, then moved to the Adventist Health Corporate office in Roseville, Adventist Health Sunbelt and Simi Valley Hospital before joining the executive team of GAMC in 1999.



Jon Giese

Vice President, Finance/CFO 

As chief financial officer, Jon's role at Glendale Adventist Medical Center is to improve efficiency and growth, helping to ensure that the hospital's award-winning services continue to be available for our patients and their families.

Jon graduated in 2003 with a Bachelor of Science degree in Business Administration, with a concentration in accounting. He began his career in Adventist Health's Audit Department, traveling to many of GAMC's sister hospitals before moving to Simi Valley Hospital in 2008, where he served as the director of the Finance and Admitting Departments. He was promoted to vice president and chief financial officer at Simi Valley in 2011 before joining the GAMC executive team as vice president of Finance/CFO in 2014.


Karen Brandt

Vice President/CNO

In her role as vice president of Clinical Services/CNO, Karen's focus is on excellence, quality and compassion in all aspects of patient care as well as various other services.

She began her career in Adventist Health at White Memorial Medical Center in 1999 as an Emergency Department staff nurse. She came to 
GAMC as a family practice nurse practitioner in 2004, and in 2009 she 
became the director of the Spine and Orthopedic Institutes. She joined the executive team in June 2013.

Karen holds a bachelor's and master's degree in nursing and is a family practice nurse practitioner.


Arby Nahapetian, MD
Vice President, Medical Affairs & Quality​
Chief Medical Officer, Southern California Region

After graduating from Yale University with a Master in Public Health, Dr. Nahapetian started his career serving in humanitarian work in Africa with the World Health Organization. He later graduated from UC Davis Medical School and completed residency and a cardiology fellowship at Harbor-UCLA Medical Center. Dr. Nahapetian has been intrigued by administrative functions and roles, which led to opportunities for developing his leadership skills. He is passionate about clinical quality and evidence-based medicine.

Dr. Nahapetian is a practicing cardiologist and electrophysiologist. He continues to practice clinical medicine in a minimal capacity as he performs his duties as Vice President.



Sharon Correa

Vice President/CIO

In her role at Glendale Adventist, Sharon has responsibility for Information Technology solutions and services, which includes Information Technology, Clinical Engineering and Telecommunications.

Sharon began her career in Adventist Health at Simi Valley Adventist and eventually worked with nearly all facilities implementing technology solutions and applications. She has over 20 years of experience in Adventist Health within IT and has been with Glendale Adventist since 2001.

Sharon strives to ensure that our business is supported through the effective deployment of technology solutions. Sharon also leads Lean Six Sigma process improvement for Glendale. Sharon has a Bachelor of Science degree in Information Technology from the University of Phoenix and is certified as a Six Sigma Green Belt.


Ramella Markarian
Vice President, Business Development & Physician Relations

Ramella received her Bachelor's degree in Business Administration and Master's degree in Health Care Administration and has served in various business development roles in health care organizations since 2000. During her time at GAMC, Ramella has been instrumental in helping to grow market share year-over-year and recruited numerous physicians to the area to meet the health care needs of our community. She consistently builds strong and trusting relationships with physicians and partners, and contributes to GAMC's business growth.

Ramella is very passionate about our community and loves to give back. She has been serving as a commissioner for City of Glendale's Community Development Block Grant Commission since 2008 and has served and held leadership roles in many community non-profit organizations. Additionally, Ramella has received many awards and recognitions, including Senator Carol Liu's 2012 business woman of the year award.



Terri Van Houten

Associate Vice President, Nursing Operations

In her role, Terri is responsible for oversight of various nursing services and works with nursing directors on unit productivity and operations, along with patient through put. She also chairs the nursing supply chain team, which has oversight for analysis and review of all equipment in consideration for use in the nursing departments.

Terri began her career with Glendale Adventist as a new graduate RN in 1997 in Medical 2 and has held various other leadership roles at GAMC including, head nurse, med-surg director and director of nursing operations. She joined the executive team in March 2013.

Terri is a registered nurse (BSN) and also has a masters degree in nursing education from the University of Phoenix.