James G. Grattan, M.D., F.A.C.C. is a practicing cardiologist with Cardiologists of Lubbock. He graduated from Stanford University in Palo Alto, California and received his medical degree from the New York Medical College in 1975. He completed his internship and residency training in internal medicine and his fellowship in cardiovascular diseases at the Mayo Clinic in Rochester, Minnesota. Dr. Grattan has been certified by the American Board of Internal Medicine in internal medicine, cardiovascular diseases, interventional cardiology and cardiac (CT) angiography. He received a special competency in echocardiography from the American Society of Echocardiography. Dr. Grattan is a founding member of the Society of Cardiovascular CT. Dr. Grattan authored a chapter in the textbook “Complimentary and Integrative Therapy for Cardiovascular Disease”.

Dr. Roberto Solís was born and raised in Guatemala City. His father, also a cardiologist, was a great influence while growing up. He had a Catholic education all his childhood and after graduating high school, he attended Francisco Marroquin University, where he graduated from Medical School in 1987. He married, Veronica and they had Ximena. While preparing for the U.S. medical boards, he started the Internal Medicine residency program at the Social Security Hospital in Guatemala City. After completing all requirements, he was accepted into the Texas Tech Health Sciences Center Internal Medicine program in 1991, where he also completed his Cardiology fellowship in 1997. Later, he worked in private practice in Lufkin, Texas for three years. In 2000, he joined Cardiologists of Lubbock, where he has been practicing for 24 years. He specializes in Interventional Cardiology.

Changing lives in a positive way is Dr. Sharif’s motto. “The evolution of cardiology as a science and practice continues to get better and better. My greatest challenge and my greatest reward are helping patients improve the quality of their lives. Applying my knowledge to help patients feel better, work better and live better gives me great satisfaction. It’s why I became a doctor.”
Educational training:

• MD: Aleppo University School of Medicine (with honors)
• Residency/Internship: Internal Medicine, Sinai Hospital, Wayne State University School of Medicine, Detroit, MI
• Chief Medical Resident: Internal Medicine, Sinai Hospital, Wayne State University School of Medicine, Detroit, MI
• Fellowship: Cardiovascular Disease, Interventional Cardiology, Brown University School of Medicine, Providence, RI
• Former Assistant Professor: Department of Internal Medicine, Michigan State University School of Medicine, Lansing, MI
• Former Chief of Cardiology: Department of Internal Medicine, Michigan State University School of Medicine, Lansing, MI
• Clinical Assistant Professor: Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX

Hospital Affiliations: Lubbock Heart and Surgical Hospital, Covenant Medical Center and University Medical Center, Lubbock, TX.

Clinics: Texas Physicians Group – Cardiologists of Lubbock and Brownfield Clinic.

In his spare time, Dr. Sharif enjoys spending time with his family, reading, music and playing tennis.

Nestor Mercado, MD, PhD, FESC, FSCAI is a board-certified interventional cardiologist specializing in structural heart disease, coronary interventions, and peripheral endovascular procedures with Cardiologists of Lubbock at Lubbock Heart Hospital. He previously served as an Assistant Professor of Medicine (Cardiology) and Director of the Structural Heart Program at the University of New Mexico in Albuquerque.

Dr. Mercado is committed to building long-term relationships with his patients grounded in trust, transparency, and open communication. His philosophy of care focuses on improving patients’ quality of life through efficient, compassionate, personalized, and evidence-based cardiovascular care.

In addition to his clinical expertise, Dr. Mercado has a strong academic and research background. His research interests include clinical outcomes in patients undergoing coronary revascularization and structural heart interventions. He has authored 10 book chapters, published 30 original manuscripts in high-impact peer-reviewed cardiology journals, and presented more than 40 abstracts at major national and international scientific meetings, including those of the American College of Cardiology, European Society of Cardiology, American Heart Association, and Transcatheter Cardiovascular Therapeutics. He also serves as a member of the American Board of Internal Medicine Interventional Cardiology Examination Committee.

Outside of medicine, Dr. Mercado enjoys traveling with his wife and son.