Obesity Ups Arrhythmia Risk After Bypass

Being overweight can more than double the odds, study found

THURSDAY, Nov. 17, 2005 (HealthDay News) -- Overweight and obese people are at especially high risk of developing a potentially fatal abnormal heart rhythm after heart surgery, a new study finds.

The study of more than 8,000 cardiac surgery patients is the first to identify a strong, independent association between excess weight and the development of this arrhythmia, called post-operative atrial fibrillation (A-Fib).

The patients in the study were grouped according to body mass index (BMI): underweight -- BMI less than 22; normal weight -- BMI of 22-25; overweight -- BMI of 25.1-30; obese I -- BMI of 30.1-35; obese II -- BMI of 35.1-40; and obese III -- BMI over 40.

Compared with patients with normal BMI, the risk of A-Fib after surgery was 18 percent higher in the overweight group, 36 percent higher in the obese I group, and 69 percent higher in the obese III group. Patients in the obese III group were nearly 2.4 times more likely to develop A-Fib than normal weight patients.

"Obesity is increasingly prevalent among patients having coronary artery bypass graft surgery," Robert H. Habib, director of cardiopulmonary research at St. Vincent Mercy Medical Center in Toledo, Ohio, said in a prepared statement.

"As many as 40 percent of [bypass] patients are obese. Although studies have linked obesity to the development of atrial fibrillation in the general non-surgical adult population, no study had linked obesity to post-surgical A-Fib," Habib said.

More information

The Heart Rhythm Society has more about atrial fibrillation.

SOURCE: American Heart Association, news release, Nov. 14, 2005
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