Global study on heart valve repair surgery will improve patient outcomes around the world


Leaking valves are a common condition amongst cardiac patients

For immediate release

LONDON, ON- Researchers at Lawson Health Research Institute and Western University had a leading role in a new global study that will change the way surgeons repair leaky valves in the heart. It’s one of the most common heart valve conditions, where many patients don’t even realize they have a leaky valve and are asymptomatic, often presenting to doctors once they are late stage into the disease.

“If the leak in the mitral valve is not repaired, a patient will have problems with fluid retention, shortness of breath and heart failure,” Says Dr. Michael Chu, Lawson Scientist and Chair/Chief of the Division of Cardiac Surgery at Western’s Schulich School of Medicine & Dentistry. “That will then lead to complications requiring hospitalization and eventually an increased risk of death.” Dr. Chu is also a cardiac surgeon at London Health Sciences Centre (LHSC).

There are two related valves in the heart that can potentially leak and lead to further complications, the mitral valve and the tricuspid valve. Traditionally, the mitral valve is surgically repaired first, with the belief that it will lead to improvements in the tricuspid valve, however, scientists have discovered that isn’t always the case. “What we were concerned with was, if we repair the mitral valve only, will the tricuspid valve still leak?” 

To answer that question, the Division of Cardiac Surgery research team engaged in a multicenter, randomized trial run by the Cardiothoracic Surgical Trials Network, an important clinical trials network from the National Heart, Lung, and Blood Institute in the United States. The study took place in 39 hospital sites across the world with more than 400 cardiac patients. Dr. Chu and his team in London worked with patients through LHSC to be the top recruiting hospital and research team in this study.  Patients were randomized in the trial, half receiving mitral valve repair alone, and half receiving mitral and tricuspid repair surgery at the same time. 

“What we found two years after the operations was that the group that had both mitral and tricuspid repair had significantly less severe residual leak of the tricuspid valve,” explains Dr. Chu. “These findings suggest that concomitant tricuspid repair is extremely effective and those patients who present with a tricuspid leak, should have both valves repaired at the same time.”

The study findings have been published in the New England Journal of Medicine, which has a high impact worldwide within the medical community, especially when it comes to medical practices. Dr. Chu, joint first author in the paper, believes these findings will have an important impact worldwide to how surgical teams repair leaking heart valves, and is extremely proud that this top tier, practice-changing research is being performed at Western’s Schulich School of Medicine and LHSC.

Moving forward, the next steps will be to follow these patients for five years and further investigate various aspects of the study, with the ultimate goal of improving long term outcomes for patients.


About Lawson Health Research Institute

Lawson Health Research Institute is one of Canada’s top hospital-based research institutes, tackling the most pressing challenges in health care. As the research institute of London Health Sciences Centre and St. Joseph’s Health Care London, our innovation happens where care is delivered. Lawson research teams are at the leading-edge of science with the goal of improving health and the delivery of care for patients. Working in partnership with Western University, our researchers are encouraged to pursue their curiosity, collaborate often and share their discoveries widely. Research conducted through Lawson makes a difference in the lives of patients, families and communities around the world. To learn more, visit

About Western

Western delivers an academic experience second to none. Since 1878, The Western Experience has combined academic excellence with life-long opportunities for intellectual, social and cultural growth in order to better serve our communities. Our research excellence expands knowledge and drives discovery with real-world application. Western attracts individuals with a broad worldview, seeking to study, influence and lead in the international community.

About The Schulich School of Medicine & Dentistry

The Schulich School of Medicine & Dentistry at Western University is one of Canada’s preeminent medical and dental schools. Established in 1881, it was one of the founding schools of Western University and is known for being the birthplace of family medicine in Canada. For more than 130 years, the School has demonstrated a commitment to academic excellence and a passion for scientific discovery. 

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Celine Zadorsky

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Lawson Health Research Institute
T: 519-685-8500 ext. 75664
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