Dr. Garratt earned his BS in Biologic Sciences (1978), MSc in Molecular Biology and Biochemistry (1979), and MD (1983) from University of California, Irvine. He completed internship at UCLA Harbor Medical Center, residency at Duke University, cardiology fellowship at UCLA Westwood, and interventional cardiology fellowship at Mayo Clinic. 

He joined Mayo Clinic staff in 1990 where he was part of the team that performed Mayo Clinic’s first laser coronary angioplasty, first directional coronary atherectomy, and first coronary stent implantation.  He organized a tele-medicine program that supported angioplasty procedures performed at hospitals without cardiac surgeons.  Between 2001 and 2004, Dr. Garratt was Chair of the Department of Cardiology at Franciscan-Skemp Medical Center (a Mayo-affiliate hospital).  

Dr. Garratt moved to Lenox Hill Hospital, New York City, in 2005.  He served as Associate Chair, Quality and Research; Director Cardiac Intervention; and Director of the Interventional Cardiovascular Fellowship Program.  

He moved to ChristianaCare in Wilmington, DE in 2015.  He serves there as the John H. Ammon Chair of Cardiology and Medical Director of the Center for Heart and Vascular Health.  

Dr. Garratt has published over 180 articles in peer-reviewed medical journals, written chapters for more than 30 cardiology textbooks and has published a book on angioplasty-related techniques.  He is chair of the NCDR Chest Pain-MI Registry Research and Publication Committee.  He has served SCAI as President (2017-2018), Director of SCAI Development and Medical Industry Relations Committee, a member of the Board of Trustees, and on numerous committees, including the Executive Committee (2014-2019).