Assistant Professor
Baylor College of Medicine
Houston, Texas, US
Director of Interventional Heart Failure
Baylor College Of Medicine
Houston, Texas, United States

Board Certifications

Internal Medicine
American Board of Internal Medicine
Advanced Heart Failure and Transplant Cardiology
American Board of Internal Medicine
Cardiovascular Disease
American Board of Internal Medicine
Cardiac Electrophysiology
American Board of Internal Medicine
Interventional Cardiology
American Board of Internal Medicine

Clinical Interests

  • Cardiovascular disease
  • Interventional cardiology
  • Advanced heart failure
  • Electrophysiology
  • Cardiac transplantation
  • Mechanical Circulatory Support
  • Peripheral Interventions


MD from All-India Institute of Medicine Science
Residency at All-India Institute of Medicine Science
Fellowship at Texas Heart Institute/ St. Luke’s Episcopal Hospital
Fellowship at Texas Heart Institute/ St. Luke’s Episcopal Hospital
Interventional Cardiology
Fellowship at Baylor University Medical Center
Residency at Emory University Hospital
Internal Medicine

Dr. Leo Simpson is an Assistant Professor at Baylor College of Medicine and is board-certified in Interventional Cardiology, Electrophysiology and Advanced Heart Failure and cardiac transplant.

Dr. Simpson earned his medical degree and completed his residency at the All India Institute of Medical Sciences. His extensive training included residency in Internal Medicine at Emory University followed by Cardiology and Interventional Cardiology fellowship at St. Luke’s Episcopal Hospital/Texas Heart Institute and then Cardiac Electrophysiology at Baylor University Medical Center in Dallas. He is affiliated with Texas Heart Institute at Baylor St. Luke's Medical Center and an active member of the Heart Failure and Cardiac Transplantation team at the Texas Heart Institute.

Dr. Simpson is a member of the American Society of Echocardiography and the American Society of Nuclear Cardiology and is a Fellow of the American College of Cardiology, Fellow of the Heart Rhythm Society and Fellow of Society for Cardiovascular Angiography and Intervention.

He is an expert in the field of percutaneously inserted biventricular mechanical circulatory support (Impella, Tandem and ECMO), both for the treatment of refractory shock, ARDS and to support high risk percutaneous coronary revascularization, as well as Electrophysiological procedures. He also specializes in Percutaneous Patent Foramen Ovale (PFO) closure, Percutaneous Atrial septal Defect (ASD) closure, and MitraClip - a less-invasive treatment option for certain people with mitral regurgitation who are not suitable for surgery.

In addition to his clinical pursuits, his primary research interest is in the field of treatment of advanced heart failure. Dr. Simpson currently runs as a sub-investigator a randomized trial study - INOVATE-HF (INcrease OF VAgal TonE in chronic heart failure, a randomized study to establish Safety and Efficacy of CardioFit for treatment of subjects with heart failure and Left Ventricular Dysfunction) in this field. He is also the co-author of multiple publications involving left ventricular assist device and cardiomyopathy.

Dr. Simpson’s clinical and research interests include advanced heart failure, interventional cardiology, complex electrophysiological procedures, high risk percutaneous coronary revascularization, cardiogenic shock, peripheral interventions, Asd/vsd Septal closure, and ARDS


American Society of Echocardiography
American Society of Nuclear Cardiology
Fellow of American College of Cardiology
Fellow of Heart Rhythm Society
Fellow of Society of Cardiovascular Angiography and Intervention
Member of The Texas Heart Institute Professional Staff
Texas Heart Institute Cardiac Society

Selected Publications

  • Nascimbene A, Hernandez R, George JK, Parker A, Bergeron AL, Pradhan S, Vijayan KV, Civitello A, Simpson L, Nawrot M, Lee VV, Mallidi HR, Delgado RM, Dong JF, Frazier OH. "Association between cell-derived microparticles and adverse events in patients with nonpulsatile left ventricular assist devices. J Heart Lung Transplant." 2014 May;33(5):470-477.
  • Angelini P, Monge J, Simpson L.. "Biventricular takotsubo cardiomyopathy: case report and general discussion." 2013;40(3):312-5.
  • Shah NR, Lam WW, Rodriguez FH 3rd, Ermis PR, Simpson L, Frazier OH, Franklin WJ, Parekh DR. "Clinical outcomes after ventricular assist device implantation in adults with complex congenital heart disease." 2013;32(6):615-20.
  • Cevik C, Nguyen HU, Civitello AB, Simpson L.. "Percutaneous ventricular assist device in hypertrophic obstructive cardiomyopathy with cardiogenic shock: bridge to myectomy." 2012;93(3):978-80.
  • Tandon A, Simpson L, Assar MD. "Unusual origin of type 1 atrioventricular block with comments on Wenckebach's contribution." 2011;24(1):9-12.
  • Simpson L, Bhella PS, Schussler JM, Grayburn PA, Assar M.. "Pacemaker laser lead extraction and reimplantation of dual-chamber implantable cardioverter defibrillator via Mustard baffle in complete transposition of great arteries." 2010;23(3):256-8.
  • Ayad RF, Assar MD, Simpson L, Garner JB, Schussler JM.. "Causes and management of drug-induced long QT syndrome." 2010;23(3):250-5.
  • Alam M, Virani SS, Simpson L, Williams SB, Wilson JM.. "Cardiac sarcoidosis: a clinical entity uncommonly recognized." 2009;36(5):501-3.
  • Alam M, Simpson L, Virani SS, Cheong B, Loyalka P, Civitello AB.. "Incidental diagnosis of interrupted aortic arch in a 72-year-old man.." 2009;36(5):494-5.
  • Mehta Puja K; Simpson Leo; Lee Eva K; Lyle Teresa A; McConnell Michael E; Book Wendy.. "Endothelin receptor antagonists improve exercise tolerance and oxygen saturations in patients with Eisenmenger syndrome and congenital heart defects.." 2008;35(3):256-61.
  • "Caseous Calcification of the Mitral Annulus." Harvinder Arora, MD, Leo Simpson, MD, Raymond. 2008 June
  • Harvinder Arora, MD, MPH Leo Simpson, MD Raymond F. Stainback, MD. "Contrast Echocardiography for Right-Sided Heart Conditions Case Reports and Literature Review.." 2008;35:35-41.
  • Idelchik GM, Simpson L, Civitello AB, Loyalka P, Gregoric ID, Delgado R 3rd, Kar B.. "Use of the percutaneous left ventricular assist device in patients with severe refractory cardiogenic shock as a bridge to long-term left ventricular assist device implantation.." 2008 January;27(1):106-11.
  • Harvinder Arora, MD, Leo Simpson, MD, Andrew Civitello MD.. "Twiddler’s Syndrome." 2007
  • Tharak R. Yarrabolu, MD, Leo Simpson, MD, Salim S. Virani, MD, Harvinder Arora, MD Joseph Navarijo, MD Raymond F. Stainback, MD.. "Images in Cardiovascular Medicine." 2007;34(3):383-5.
  • Harvinder Arora, MD, Leo Simpson, MD, Reynolds Delgado, Andrew Civitello MD.. "A 26-Year-Old Female With Nonischemic Cardiomyopathy Status/Post Biventricular-Implantable Cardioverter Defibrillator Implantation Presents After Receiving a Shock From her ICD." 2007
  • G.M. Idelchik, L. Simpson, P. Loyalka, A.B. Civitello, I.D. Gregoric, B. Kar.. "Use of the percutaneous left ventricular assist device as a “bridge-to-bridge” in patients with severe refractory cardiogenic shock. Cardiovascular Revascularization Medicine." 2007 April;8(2):146.
  • Divay Chandra, MD, Biswajit Kar, MD, Gary Idelchik, MD, Leo Simpson, MD, Pranav Loyalka, MD, Igor D. Gregoric, MD, Reynolds M. Delgado III, MD.. "Usefulness of Percutaneous Left Ventricular Assist Device as a Bridge to Recovery from Myocarditis.." 2007;99(1):1755–1756.