Focus on heart disease research

February 1, 2006

Cardiovascular disease is the number one killer in Canada, accounting for about a third of all deaths, according to the Heart and Stroke Foundation of Canada. February is Canada’s official heart month and a good opportunity to look at some of the OHRI’s leading edge research in this area, including:
• Studying the molecular biology of cholesterol transport
• Investigating stem cell therapy to regenerate heart muscle
• Tracking cardiac arrest survival rates across the country
• Plus research on hypertension, stroke, and deep vein thrombosis.

Cholesterol is a fatty substance associated with plaque build-up in blood vessels. Dr. Xiaohui Zha is studying a cholesterol transport protein called ABCA1. High levels of this protein are correlated with high levels of “good cholesterol” and low levels of “bad cholesterol”. Dr. Zha’s research is bringing a greater understanding of the molecular relationship between ABCA1 and cholesterol. This could one day lead to new drugs to control cholesterol levels and decrease the risk of heart disease.

Stem cell therapy
Stem cells found in early embryos can give rise to all of the hundreds (perhaps thousands) of specialized cell types in the body. Dr. Lynn Megeney and Dr. Michael Rudnicki were the first in the world to identify a population of cells in adult heart tissue with stem cell-like activity. Their experiments suggest that with the right stimulation, stem cells in the heart may be coaxed into producing new functioning heart muscles in people suffering from chronic heart disease or heart attacks. Dr. Megeney (who is also the Mach-Gaensslen Foundation Chair in Cardiac Research) and Dr. Rudnicki (who is also the Director of Canada’s Stem Cell Network ) have founded a company called StemPath to bring their discoveries to patients as quickly as possible.

Cardiac Arrest
While the chance of surviving a heart attack is more than 90 percent, survival drops dramatically if the heart fully stops beating (cardiac arrest). The chance of surviving a cardiac arrest in Canada is only about five percent, but this percentage can vary greatly from city to city. That was one of the surprise results of a study led by Dr. Christian Vaillancourt. Even more surprising was the fact that many small and big cities didn’t even track cardiac arrest survival rates. Despite the patchy data, Dr. Vaillancourt’s study showed that cities with higher rates of bystander CPR tended to have higher cardiac arrest survival rates. With the attention generated by the study, Dr. Vaillancourt hopes more cities will start keeping better track of this type of data. Dr. Ian Stiell also researches cardiac arrest survival and his latest study – the largest of its kind - confirmed that bystander CPR has a huge impact. Dr. Stiell’s work shows that bystander CPR increases cardiac arrest survival by 3.7 fold and doubling Ontario’s bystander CPR rate from 15 to 30 percent could save an additional 350 lives every year. The study also shows that pre-hospital advanced life support (ALS) by paramedics does not result in increased survival of cardiac arrest victims if bystander CPR rates are low. Drs. Vaillancourt and Stiell are both members of the Canadian Cardiovascular Outcomes Research Team (CCORT), which recently received prestigious awards for knowledge translation and impact on cardiovascular medicine.

Dr. Rhian Touyz is the Canada Research Chair in Hypertension. She is studying the smooth muscle cells that form the walls of our blood vessels. Changes in these cells can lead to high blood pressure (hypertension) and increased risk of serious heart disease including heart attack and heart failure. Dr. Touyz is a clinician-scientist working both in the clinic with patients and in the laboratory with experimental animals. She focuses on translational research, which aims to bridge the gap between basic and clinical science.

Deep Vein Thrombosis
Dr. Phil Wells is the Canada Research Chair in Venous Thromboembolic Diseases. He developed a model to improve diagnosis of deep blood clots in the legs (Deep Vein Thrombosis). This condition is often called a “silent killer” because it is difficult to diagnose, but can be deadly if blood clots dislodge and travel to the lungs.

A stroke is a sudden loss of brain function, usually caused by a blood clot blocking blood flow to the brain. Dr. Antoine Hakim leads the Canadian Stoke Network, which includes many OHRI researchers investigating various aspects of stroke prevention and treatment. Projects focus on areas such as finding the triggers of brain cell death, studying the brain’s natural repair mechanisms, and developing new treatments involving stem cells and gene therapy.

Note: The Ottawa Hospital Research Institute is the research arm of The Ottawa Hospital and a major part of the University of Ottawa Faculties of Medicine and Health Sciences. The research described above was supported by grants from many agencies, including the Heart and Stroke Foundation of Canada and the Canadian Institutes of Health Research.