Our Team
Jennifer Lawton, M.D.
Cardiac Surgeon-in-Charge
Chief of the Division of Cardiac Surgery
Director of the Cardiac Surgery Research Laboratory
Lawton Laboratory
The Lawton laboratory investigates mechanisms underlying the myocardial protection provided by the adenosine triphosphate-sensitive potassium channel by utilizing novel cellular models, genetically altered mice, an isolated mouse heart model and a large animal model. The laboratory seeks to clarify these mechanisms in an effort to reduce morbidity and mortality secondary to cardiovascular disease. In addition to the goal of translating the findings of cardioprotection as a component of cardioplegia, the lab also seeks to identify strategies and pharmacologic methods of neuroprotection in cardiac surgery.
Learn More About Dr. Lawton’s Lab
Hamza Aziz, M.D.
Assistant Professor of Surgery
Dr. Aziz’s research efforts focus on understanding the development of ascending aortic aneurysm. Previously, Dr. Aziz had found that a gene responsible for cell guidance and migration, ROBO4, was mutated in 1-2% of patients with bicuspid aortic valve (BAV) and ascending aortic aneurysm (AsAA). Animal models with mutated ROBO4 showed mild phenotype of BAV/AsAA. To expand on this research, Dr. Aziz works with a collaborator at the Johns Hopkins Institute of Genetic Medicine to develop a technique for single cell RNA sequencing to determine why the majority of thoracic aortic aneurysms have spatial localization to either root or ascending. Aziz collaborates with researchers Dr. Elena MacFarlane and Dr. Harry Dietz III.
James Gammie, M.D.
The James T. Dresher, Sr. Professor of Cardiac Surgery
Surgical Lead and Co-Director, Johns Hopkins Heart and Vascular Institute
Cardiac Surgeon-in-Chief, Johns Hopkins Health System
Gammie Lab
Dr. James Gammie’s research focuses on improving the surgical treatment of tricuspid and mitral valve disease and other heart structure diseases through minimally invasive interventions, cardiovascular device development and improving patient outcomes after cardiac surgery.
Ahmet Kilic, M.D.
Associate Professor of Surgery
Kilic Lab
Dr. Ahmet Kilic joined the Johns Hopkins Division of Cardiac Surgery as an associate professor in 2017. Kilic’s areas of clinical research include advancing heart failure surgical treatment with a special interest in heart transplantation and mechanical circulatory support. Kilic’s research is focused on improving surgical treatment for heart failure and patient outcomes.
Chetan Pasrija, M.D., M.S.
Pasrija Lab
Dr. Pasrija specializes in heart and lung transplantation, aortic surgery and the surgical treatment of ischemic heart disease. He has published extensively on the topics of heart and lung transplant, massive pulmonary embolism, chronic thromboembolic pulmonary hypertension, and minimally invasive left ventricular assist device implantation. As a trainee, Dr. Pasrija was heavily involved with the surgical implantation and postoperative management of the first cardiac xenotransplant performed in the world at the University of Maryland. During his time as a faculty member at Vanderbilt University, he was a part of one of the largest heart and lung transplant programs in the United States. His research focuses on cutting-edge technologies to expand the donor pool, including normothermic regional perfusion. Dr. Pasrija was co-surgeon in a combined heart-lung transplant with a groundbreaking 9.5-hour period of time without any blood flow using a novel 10 degrees Celsius cooler.
Rachael Quinn, Ph.D., M.S.
Quinn Lab
Dr. Quinn’s research focuses on the surgical treatment of structural heart disease, with a primary focus on mitral and tricuspid valve disease. In collaboration with Dr. James Gammie, Dr. Quinn’s primary objective is to develop animal models of structural heart disease, including a swine model of functional mitral regurgitation, and to develop cardiovascular medical devices, specifically transcatheter annular repair. Dr. Quinn’s lab uses a 3D structured light scanner and to evaluate native, diseased and repaired valves using computer-aided drafting software in order to predict the likelihood of repair success. Dr. Quinn also collaborates on clinical research projects related to improving patient outcomes after cardiac surgery.
Hanghang Wang, M.D., Ph.D.
Wang Lab
With a focus on precision medicine, Dr. Wang is dedicated to creating personalized diagnostic and treatment modalities for cardiovascular diseases, integrating cutting-edge research into clinical practice.
Learn More About Dr. Wang’s Lab
Glenn Whitman, M.D.
Professor of Surgery
Whitman Lab
Dr. Whitman’s research focuses on quality outcomes and improving management for patients during and after their procedure, particularly in the setting of an ICU. He is currently working on identifying and eliminating intraoperative causes of acute kidney injury during cardiac surgery through the use of urinary biomarkers. Dr. Whitman is investigating the relationship between delivered O2, lactate and acute kidney injury during cardiac surgery.
AlleaBelle Bradshaw, M.D.
Cardiac Surgery Research Fellow
General Surgery Resident
MedStar Georgetown University-Washington Hospital Center
2024-2027
Dr. Bradshaw is a postdoctoral research fellow in cardiac surgery at the Johns Hopkins School of Medicine. She earned a bachelor’s degree in biology and psychology from Ouachita Baptist University and obtained a medical doctorate from the University of Arkansas for Medical Sciences. She completed three years of general surgery residency at MedStar Health Georgetown University Hospital and Washington Hospital Center prior to starting a three-year fellowship in the lab. Her primary research focus is on optimizing strategies for myocardial protection and gaining an improved understanding of myocardial injury after cardiac surgery. She is pursuing a career as a cardiac surgeon-scientist.
See a list of her publications.
Shivani Shirodkar, MBBS, M.P.H.
Research Fellow
Department of Cardiac Surgery
2025-2026
Shivani Shirodkar is a postdoctoral research fellow in cardiac surgery at the Johns Hopkins School of Medicine. She received her Bachelor of Medicine and Bachelor of Surgery from Sassoon General Hospital, Pune, India. She then went on to get her Masters in Public Health from Johns Hopkins Bloomberg School of Public Health. After working in the cardiac transplantation lab as a research fellow for a year, Dr. Shirodkar is now focusing on cardioprotection and neuroprotection strategies integrated with transplantation.
Christopher Rumer, M.D.
Cardiac Surgery Research Fellow
General Surgery Resident
2025-2027
Dr. Rumer is a postdoctoral research fellow in cardiac surgery at the Johns Hopkins School of Medicine. He earned a bachelor's degree in biochemistry from the University of Washington and remained in the Pacific Northwest to earn his medical degree from the University of Washington School of Medicine. He completed two years of general surgery residency in Vermont before beginning a two-year research fellowship in the lab. His primary research focus is on improving the surgical treatment of tricuspid and mitral valve disease through minimally invasive interventions and device development.
Timothy Sank, B.S.
Research technician
Collaborators
| Researcher Name | Division |
|---|---|
| Brian O'Rourke, Ph.D. | Cardiology |
| Lee Goedell, M.D., M.P.H. | Anesthesiology |
| Mary Beth Brady, M.D. | Anesthesiology |
| Jeffrey Michael Dodd-o, M.D., Ph.D. | Anesthesiology |
| Brian Cho, M.D. | Anesthesiology |
| Elena Gallo MacFarlane, Ph.D. | Genetic Medicine |
| Harry C. Dietz III, M.D. | Genetic Medicine |
| Mary Ann Wilson, Ph.D. | Neurology and Neuroscience |
| Lee J. Martin, Ph.D. | Pathology and Neuroscience |
| Joseph Scafidi, M.S., D.O. | Neurology |
| Sung-Min Cho, D.O., M.H.S. | Neurology |
| Kannan Rangaramanujam, M.S., Ph.D. | Ophthalmology and Nanomedicine |
| Allen Eghrari, M.D., M.P.H. | Ophthalmology |
| Lauren Leigh Jantzie, Ph.D. | Neurosurgery |
| Dody Robinson, M.D. | Neurosurgery |
Past Residents
View some of our past surgery residents involved in the Johns Hopkins Cardiac Surgery Research Lab.
| Name | Year Started |
|---|---|
| Michelle Carvajal, M.D. | 2025 |
| Yashutosh Joshi, MBBS | 2025 |
| Jessica B. Briscoe, M.D. | 2023 |
| Zachary Darby, M.D. | 2022 |
| Ifeanyi Chinedozi, M.D., M.B.A. | 2022 |
| Jin Kook Kang, M.D. | 2022 |
| Kate Verdi, M.D. | 2021 |
| Eric Etchill, M.D. | 2021 |
| Hannah Rando, M.D. | 2021 |
| Cecilia Lui, M.D. | 2017 |
| Xun Zhou, M.D. | 2017 |
| Charles Fraser, M.D. | 2017 |
| Todd Crawford, M.D. | 2015 |
| J. Trent Magruder, M.D. | 2014 |
| Joshua C. Grimm, M.D. | 2013 |
| Claude Beaty, M.D. | 2011 |
| Tim George, M.D. | 2010 |
| George Arnaoutakis, M.D. | 2009 |
| Geoff Allen, M.D. | 2008 |
| Eric Weiss, M.D. | 2007 |
| Lois Nwakanma, M.D. | 2006 |
| Jason Williams, M.D. | 2005 |
| Chris Barreiro, M.D. | 2004 |
| Torin Fitton, M.D. | 2002 |
| Stephen Cattaneo, M.D. | 2001 |
| David Caparrelli, M.D. | 2001 |
| Eric Peck, M.D. | 2000 |
| Jay Shake, M.D. | 2000 |
| Peter Walinsky, M.D. | 1999 |
| Jorge Salazar, M.D. | 1997 |
| John Doty, M.D. | 1997 |
| Elaine Tseng, M.D. | 1994 |
| Kirk J. Fleischer, M.D. | 1992 |
| Malcolm V. Brock, M.D. | 1992 |
| A. Marc Gillinov, M.D. | 1991 |
| William Curtis, M.D. | 1991 |
| Peter W. Cho, M.D. | 1991 |
| Mark J. Redmond, M.D. | 1991 |
| Michael A. Acker, M.D. | 1990 |
| Patrick Devaleria, M.D. | 1989 |
| R.C. Stewart Finney, M.D. | 1989 |
| Peter S. Greene, M.D. | 1988 |
| Peter J. Horneffer, M.D. | 1988 |
| Charles D. Fraser, M.D. | 1987 |
| Wen Cheng, M.D. | 1987 |
| Bruce R. Rosengard, M.D. | 1986 |
| Timothy S. Hall, M.D. | 1986 |
| Duke E. Cameron, M.D. | 1985 |
| Sara J. Shumway, M.D. | 1984 |
| Stuart R. Scott, M.D. | 1984 |
| Steven F. Bolling, M.D. | 1983 |
| Alfred S. Casale, M.D. | 1983 |
| George J. Magovern Jr., M.D. | 1982 |