Bariatric surgery lowers risk of future cardiovascular disease



Researchers at McMaster University in Hamilton, Ontario, Canada, have reported that participants with cardiovascular disease and severe obesity who underwent bariatric surgery had fewer major adverse cardiovascular events (MACE), compared with people with similar conditions who did not have the surgery.

The study, ‘Bariatric Surgery and Cardiovascular Outcomes in Patients With Obesity and Cardiovascular Disease: A Population-Based Retrospective Cohort Study’, published in the American Heart Association journal Circulation. Sought to determine the association between bariatric surgery and MACE among patients with cardiovascular disease and severe obesity.

"There has been hesitancy in looking at patients with significant cardiac disease as potential candidates for bariatric surgery," said Dr Mehran Anvari, professor of surgery at McMaster University in Hamilton, Ontario, and the study's senior author. "We thought it would be good to have a look at whether there was a difference between those who went for surgery compared to patients who could have qualified but either were not referred or did not proceed to surgery."

Drawing from medical records in Ontario, researchers matched 1,319 people with heart disease or heart failure who had bariatric surgery against an equal number of people with similar circumstances who did not have the procedure.

After a median follow-up of 4.6 years, nearly 20% of those who did not have surgery experienced an adverse outcome – ranging from heart attack or stroke to heart failure hospitalisation or overall mortality – compared to about 12% who did have surgery. That translated to a 42% reduction in risk.

"So, we certainly see that bariatric surgery has a higher reward than the additional risk. When you carry less weight, your heart has to work less to pump blood. So, there is less strain on your heart, but there is also improvement in other cardiovascular risk components, such as lowering of triglycerides and cholesterol."

The new research is a retrospective cohort study, looking back at patient outcomes. Anvari said his team has already begun to follow it up with a randomised controlled trial.

"This is level two evidence and now we need level one evidence," he said.