Richard D Weisel, BA, MD

Emerita/Emeritus Scientist, Toronto General Hospital Research Institute (TGHRI)
Keywords: cardiac regeneration, cardiac surgery, aging, cell transplantation, tissue engineering, cell and gene therapy, clinical trials, ischemic heart disease, heart failure

Richard Weisel is a Cardiovascular Surgeon at the Toronto General Hospital, a Senior Scientist (Emeritus) at the Toronto General Research Institute and a Professor of Cardiac Surgery (Emeritus) at the University of Toronto. He trained in General Surgery at Boston University where he was an NIH trainee in Academic Surgery. He completed a residency in Cardiothoracic and Vascular Surgery in Toronto in 1978 and has been a member of the Division since then. He was the Director of Research for the Department of Surgery (1990-1995), Chairman of the Division of Cardiac Surgery (1998-2009) and Director of Toronto General Hospital Research Institute (2005-2011). He was the Chairman of the Cardiothoracic Surgical Trial Network (2014-2019, funded by NIH and CIHR) and Editor-in-Chief of the American Association for Thoracic Surgery Journals from 2014 to 2021. He was elected Fellow of the Canadian Academy of Health Sciences in 2016 and a member of the Order of Canada in 2023.
In addition to cardiac surgery, he devoted his career to basic and clinical investigations. His most important contribution was the training two generations of Cardiac Surgical Scientists who have assumed leadership positions in academic cardiac surgery in Canada and around the world.  

The goal of our research program is to restore normal cardiac function to patients with cardiac diseases. In the laboratory, we discovered that injecting stem cells into the cardiac region injured by a heart attack improved function and prevented death from heart failure. We then performed a series of clinical trials and found that bone marrow stem cells improved heart function but the benefits were not as good as in experimental models. We documented diminished marrow stem cell function in older patients undergoing cardiac surgery and evaluated different methods to improve their function before injecting them into the heart. The enhanced stem cells improved cardiac function but only marginally. Our basic research continues to evaluate alternative methods to enhance cell therapy to restore normal cardiac function to the elderly victims of a heart attack.

In the laboratory we found that bone marrow transplantation from young animals restored the ability of marrow stem cells to repair the heart after injury. The young bone marrow cells engrafted in the bone marrow and also migrated to the injured heart and contributed to the restoration of cardiac function.

We also have evaluated a variety of tissue engineering constructs containing both cells and cytokines which restore cardiac function after injury. Others have applied cell seeded constructs to the epicardium in patients after cardiac injury and this approach may eventually have clinical benefit.

For a list of Dr. Weisel's publications, please visit PubMed or Scopus.

Emerita/Emeritus Scientist, Toronto General Hospital Research Institute (TGHRI)

Emeritus Professor of Cardiac Surgery, University of Toronto
Full Member, Graduate Faculty, Institute of Medical Science, University of Toronto