THURSDAY, May 8, 2014 (HealthDay News) -- Weight-loss surgery
not only helps obese people drop pounds, but it may also prevent
the dangerous heart rhythm disorder known as atrial fibrillation,
according to new research.
Scientists from the Mayo Clinic found that significantly fewer
patients who underwent weight-loss surgery, also known as
"bariatric" surgery, developed atrial fibrillation -- a rapid and
irregular heartbeat -- than those who didn't have weight-loss
surgery. Atrial fibrillation affects more than 2.7 million American
Common types of weight-loss surgery include the gastric band, in
which a band is placed to create a small stomach pouch, and gastric
bypass, which allows food to bypass parts of the stomach.
The study is the first to demonstrate a relationship between
bariatric surgery and lower rates of atrial fibrillation in a large
patient sample. Weight-loss surgery has already been shown in prior
research to improve or resolve many obesity-related conditions,
including type 2 diabetes, high blood pressure and some types of
"I think we know that bariatric surgery does good things for
people from a cardiovascular risk profile," said Dr. Michael Gold,
director of cardiology at Medical University of South Carolina, who
wasn't involved in the research. "Now we're starting to go
downstream from that to look at more long-term impacts . . . and
atrial fibrillation is one of those. It's a logical consequence of
what we already know."
The study, from Dr. Yong-Mei Cha and colleagues, was scheduled
for presentation Wednesday at Heart Rhythm 2014, the Heart Rhythm
Society's annual conference, in San Francisco. Research presented
at scientific meetings typically has not been peer-reviewed or
published, and results are considered preliminary.
More than one-third of American adults are classified as obese,
with a body mass index (BMI) exceeding 30. BMI is a measurement
based on height and weight. About 160,000 weight-loss surgeries are
performed each year in the United States, according to the American
Society for Metabolic and Bariatric Surgery. Several different
surgical procedures exist, but all seek to reduce the capacity of
the stomach, which allows fewer calories to be consumed and/or
Obesity is a known risk factor for atrial fibrillation, which
can trigger stroke and other dangerous problems when the top
chambers of the heart, called the atria, quiver erratically --
sometimes faster than 300 times per minute.
The Mayo Clinic researchers examined data from 438 patients with
a BMI of 40 or higher who were identified as good candidates for
bariatric surgery, with about three-quarters of them electing to
undergo the procedure.
While the incidence of atrial fibrillation was not markedly
different between the surgical and nonsurgical group at the start
of the study, only 6 percent of the surgical patients developed the
abnormal heartbeat condition over the next seven years, compared to
16 percent of the nonsurgical patients, according to study
"I think this is further evidence that maintaining a normal body
weight or weight loss is important for cardiovascular health," said
Gold, who is also second vice president of the Heart Rhythm
Society. "It provides further impetus for clinicians to think about
bariatric surgery sooner, particularly cardiologists. We can be
more proactive in our treatment."
Dr. John Day, director of heart rhythm services at Intermountain
Heart Institute in Murray, Utah, noted that North America has the
highest prevalence of atrial fibrillation in the world, largely
because of its obesity epidemic. Prior research has indicated that
obesity increases the risk of atrial fibrillation by more than 50
percent, he said.
"The message here is that getting the weight off can have a
powerful reversal effect on atrial fibrillation," Day said. "Atrial
fibrillation is a reversible condition, it's not set in stone. This
is a message of hope for so many patients suffering from it."
The American Society for Metabolic and Bariatric Surgery has
details on various types of