Jan. 31, 2011 -- Severely obese patients who have gastric bypass surgery can expect obesity-related heart abnormalities to stabilize or partially reverse, new research suggests.
''The cardiac size and function were restored toward normal in the people who got the gastric bypass surgery," says researcher Sheldon Litwin, MD, chief of cardiology at the Medical College of Georgia.
''We hypothesized that it would have this effect, but it is nice to prove it," says researcher Sheldon Litwin, MD, chief of cardiology at the Medical College of Georgia.
"We think this study suggests that the large amount of weight loss associated with gastric bypass surgery may lower their cardiovascular risks long-term," Litwin says.
The study results support the use of bariatric surgery to prevent cardiovascular complications, according to Litwin.
The findings are similar to previous studies, he says, but his study included more people and a longer follow-up than other studies. The new study also compares those who had the surgery with those who did not, finding the surgery patients fared better in terms of not only weight loss but heart functioning.
The study is published in the Journal of the American College of Cardiology.
Severely obese people experience what is called adverse ''cardiac remodeling," Litwin says. The left atrium and the left ventricle commonly get bigger. The left atrium receives oxygen-rich blood from the lungs and pumps it down into the left ventricle, which pumps it out to the body.
When the left ventricle gets too thick and too big, it can affect people's ability to exercise, Litwin tells WebMD. The enlargement of the left atrium boosts the risk of an abnormal heart rhythm, atrial fibrillation, in turn increasing the risk of stroke, he says.
These cardiac changes also increase the risk of heart failure and death.
In the study, the 423 patients who had the surgery were on average age 42; the 733 who didn't have surgery were on average age 46.
All patients in the surgery group had the Roux-en-Y procedure. In this surgery, the stomach is made smaller by creating a small pouch at the top of the stomach using surgical staples or a plastic band, and then the stomach is connected to the middle part of the small intestine, bypassing some of the small intestine.
As a result, the patient eats less and absorbs less food.
At the study's start and end, the researchers measured height, weight, heart rate, blood pressure, blood glucose, cholesterol, and other factors. The researchers performed echocardiography, the use of ultrasound to study the heart's motions and structure, on most of the patients at the study's start and two years later.
Effect of Gastric Bypass on the Heart
At the study's start, the average body mass index (BMI) of those who had surgery was 47.9 (30 and higher is termed obese; 40 and up severely obese). The BMI of those who didn't have surgery averaged about 45.