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Associate Program Directors


Karen Chacko, MD was born and raised in the San Francisco Bay Area.  She attended undergraduate and medical school at UC San Diego. She completed her internship, residency and chief residency here at the University of Colorado in the Primary Care track. She has been GIM faculty here since completing her training. Karen enjoys hiking, running, camping, biking and cooking with her two beautiful girls and husband. Dr. Chacko is the senior Associate Program Director and the Program Director of the Primary Care track.



Mel Anderson, MD is from Texas, where he graduated AOA from the University of Texas (Houston) in 1994. He completed Internal Medicine Residency Training, a Chief Residency, and several years as an academic faculty member at the David Grant USAF Medical Center in Northern California before joining the faculty at Brown University and the Providence VAMC for four years. Dr. Anderson joined the University of Colorado faculty in 2005 and is currently an Associate Professor of Medicine. Mel has served as an Associate Program Director since 2006, was the Interim Program Director from May 2016 to September 2017, directs the Clinician/Educator Pathway, Wednesday Education Sessions, and teaches on the inpatient service at the Denver VAMC.

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Dan Heppe, MD was born and raised in Colorado. He attended Medical School and subsequently completed residency and chief residency here at the University of Colorado. He completed his training in 2012 and joined the Hospital Medicine Group at Denver Health Medical Center.  After four excellent years at that institution he recently joined  the Hospital Medicine group at the Denver VAMC.  His academic interests include resident education, alcohol withdrawal and prevention and substance abuse.  He is the father of two beautiful daughters (pictures available upon request). Outside of medicine he enjoys skiing,  hiking, camping, playing music and spending time with family.

Mark Kearns
, MD  is originally from small town Nebraska and grew up in Dayton, OH. He returned to Nebraska to attend the University of Nebraska-Lincoln for his undergraduate degree. He subsequently received his medical degree from the University of Nebraska Medical Center in Omaha where he graduated AOA. After completing his residency and chief residency at the Ohio State University, Mark moved to Denver in 2007 to pursue Pulmonary/Critical Care fellowship training at the University of Colorado. Following completion of fellowship, Mark has been on faculty at the University of Colorado Hospital and Denver Health Medical Center. He joined the residency program as an Associate Program Director in 2015 with particular interest in mentorship, sub-specialist career development, and critical care ultrasound education. He also serves as the residency program site director at Denver Health Medical Center. Outside of medicine, Mark enjoys playing guitar, college football (Go Big Red!), attending concerts, checking out Denver’s burgeoning restaurant scene, and pitching hours of batting practice to his two sons.​

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Darlene Tad-y, MD is originally from Chicago, IL. She completed her residency training at Lutheran Medical Center in Brooklyn, NY and fellowship training at Johns Hopkins Bayview Medical Center in Baltimore. She is a member of the hospital medicine group at the University of Colorado. She directs the Hospitalist Training Program, and teaches about QI and the business of medicine. Darlene also enjoys cooking, rock climbing and camping. She joined the residency program in 2011.

Katie Suddarth, MD is originally from Philadelphia, PA. She went to Dartmouth College then moved to Denver to attend the University of Colorado School of Medicine where she graduated AOA. After medical school, Katie entered the Primary Care Track of the University of Colorado Internal Medicine Residency Program. She completed her training in 2009, followed by a chief resident year. She is currently a primary care physician at the University of Colorado and became an Assistant Program Director for the residency program in 2011. Her interests outside of medicine include hiking, running, snowshoeing, and traveling.

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Brian Graham, MD
is an Assistant Professor in the Divison of Pulmonary
Sciences and Critical Care Medicine at the
University of Colorado. He completed Bachelor’s and Master’s degrees in electrical engineering at MIT, medical school at Harvard, and residency in internal medicine and pulmonary-critical care fellowship at the University of Colorado. His clinical work is primarily in the areas of pulmonary hypertension and hereditary hemorrhagic telangiectasia. His research studies the inflammatory pathogenesis of pulmonary hypertension, primarily using a model of schistosomiasis-induced disease. His research is funded by a K08 from the NHLBI, the Parker B. Francis Foundation, Gilead, Pfizer, the ATS/Pulmonary Hypertension Association, and Novartis. Outside of medicine, Brian enjoys skiing and hiking with his wife and son. Brian leads the research track and helps residents applying to fellowship.

Brian Graham


Lisa Davis, MD, MSCS grew up in a rural town in Arkansas. She completed her undergraduate degree at Brigham Young University and her medical degree from the University of Colorado. She completed her internship, residency and Rheumatology research fellowship at the University of Colorado. She joined the faculty at Denver Health Medical Center in 2011, where she practices Rheumatology. Her areas of research include adverse drug events, outcomes research, and health services research. She joined the residency program as an Associate Program Director in 2016, and works with the research track and categorical residents. She has a son and a daughter and enjoys cooking, cycling, hiking, and most outdoor sports. 


Director, PSTP Track

Arthur Gutierrez-Hartmann, MD was born in Mexico City and grew up in San Antonio, Texas, with Arthur.jpg
Spanish as his first language. He received a BA in Chemistry in 1971 from the University of Texas at Austin, and then graduated with an MD from the University of Texas Southwestern Medical School (UTSW) in 1975. From 1971-1977, he also pursued graduate studies purifying yeast citrate synthase from yeast mitochondria in Dr. Ron Butow’s lab in the Biochemistry Dept at UTSW. From 1977-80, he completed Internal Medicine residency training at Stanford University Hospital, and from 1980-83, he completed a Molecular Endocrinology training fellowship with Dr. John Baxter at UCSF. After an initial faculty position at UCSF (1983-85), he was recruited to the University of Colorado HSC in 1985, where he was a founding member of the MD/PhD Training Program (1985; now MSTP), the Molecular Biology Graduate Program (1986), the Cancer Center (1987), the Reproductive Biology Graduate Program (2004), the CCTSI TL1 (2008), and the Physician-Scientist Training Program (2011). Arthur has served in leadership positions in national associations dealing with graduate and physician-scientist training, on Council of the American Cancer Society (ACS), and he serves on multiple editorial boards, including Associate Editor of Molecular Endocrinology. Arthur has been selected for many awards and visiting professorships, including: an A. P. Giannini/Bank of America Fellowship; a PEW Scholar Award in the Biomedical Sciences; elected to the American Society of Clinical Investigation; a NSF-CNRS Visiting Scientist, IGBMC, Illkirch, France; the 2002 SACNAS Distinguished Scientist of the Year Award; the 2008 AACR Jane Coffin Wright - Minority in Cancer Research Award; the 2009 Endocrine Society’s Distinguished Educator Award; and the inaugural ASBMB 2010 Ruth Kirchstein Diversity in Science Award. The main focus of the AGH laboratory is to determine the role of ETS transcription factors in epithelial cell development and tumorigenesis, with a focus on pituitary mammary and GI model systems. He has been supported by NIH R01 grants to pursue this research work, with PEW, ACS, DOD and NSF also providing support. As a clinician he attends patients with endocrine disorders, focusing on pituitary tumors and thyroid cancer. Finally, Arthur has been highly committed to the recruitment and training of women and underrepresented students to all aspects of the biomedical workforce.


Karen Shea, MD, Assistant Director for Housestaff DiversityShea.jpg

I grew up in a small, rural town in Southern Colorado population 2,927. My Dad was one of four family physicians working in the community.  At a young age, I was able to witness firsthand  the wide range of health disparities that existed just within our small town.  Because my Dad spoke Spanish and shared similar cultural preferences and beliefs, he was able to effectively educate and treat numerous patients who may have otherwise not accessed healthcare.

I completed my undergraduate training at Adams State College in the San Luis Valley in 1999 where again I witnessed the health struggles of the migrant farmers and the disproportionate amount of diabetes in this community during my volunteer work at the regional hospital.  It was during this time that I met with the CU Office of Diversity and Inclusion during a visit to my school. This outreach from CU left a great impression on me. They cared about diversity and offered the support and guidance I needed to gain acceptance to CU medical school.  I completed my Internal Medicine Residency and Geriatric Fellowship training at the University of Colorado. 

Fifteen years after embarking on a career in medicine, I continue to reflect upon my past experiences. These experiences have lead me to realize that a diverse healthcare workforce  is vital to providing quality patient care. I am actively involved in both recruitment and educational endeavors for our Internal Medicine Residency program and have taken a lead role in promoting diversity amongst our housestaff. In addition, I serve as Medical Director for Home Based Primary Care at the VA Medical Center providing care for the most frail and vulnerable veterans in our community. In my off time I enjoy cooking, jogging, Zumba and going on adventures with my husband and two small children.

I welcome you to contact me anytime at to discuss our program further.


Karen L. Shea , MD

Assistant Director for House staff Diversity

Assistant Professor, Division of Geriatric Medicine

University of Colorado, School of Medicine Alumni 2004

University of Colorado, Internal Medicine Residency 2007


University of Colorado, Geriatric Medicine Fellowship 2008