Weight-reduction surgery has helped many overweight and obese people lose weight and improve their health. It’s a win-win for them.

The value of weight-reduction surgery for those who have already had a heart attack has been less clear. Heart patients are viewed as a fairly vulnerable group for any surgery, and those with a high body mass index and a history of heart attack are at an even higher risk.

Heart patients who had weight-reduction surgery had half the risk of death, a lower risk of heart attack and a lower risk of heart failure compared to those who did not have surgery.

The worry has been that despite the benefits weight-reduction could bring, the risks of the operation for obese heart patients might easily outweigh the benefits.

To get a clearer picture of how the risks and benefits of weight-reduction surgery stack up, researchers at the Karolinska Institute in Sweden looked at the trends between weight-reduction surgery and subsequent heart attacks, stroke and death in people with severe obesity who had experienced a prior heart attack.

“It is well known that obesity is associated with an increased risk for Type 2 diabetes and heart disease,” said the study’s lead author, Erik Näslund, a professor in the department of clinical sciences. “It has also been shown that weight-reduction surgery can improve Type 2 diabetes and cardiovascular disease.” But, he added, it had not been proven that weight-reduction surgery could help heart patients reduce their risk of another heart attack.

Researchers compared data on over 500 severely obese patients who had heart attacks from 2005 to 2018 and then had either gastric bypass surgery or sleeve gastrectomy surgery based on data from two health registries. Each study participant who had had weight-reduction surgery was matched to someone who had the same degree of obesity, but had not had surgery. The average BMI of both groups was 40. Surgical and non-surgical patients were also matched according to gender, age, health status and health history.

There were clear benefits. Heart patients who had weight-reduction surgery had half the risk of death, a lower risk of heart attack and a lower risk of heart failure compared to those who did not have surgery. There was no significant difference in the risk of stroke between the surgery and non-surgery groups.

One year after surgery, patients in the surgery group weighed considerably less, and their median BMI had dropped to 29. Weight loss alone was likely not the driving force in the association between surgery and decreased risk of heart problems, researchers said. Two years after surgery, researchers noted other health improvements in patients who had had the surgery:

  • Nearly 70 percent of patients saw their sleep apnea go into remission.

  • Hypertension went into remission in 22 percent of those receiving surgery.

  • Rates for cholesterol and triglyceride levels dropped.

  • Over half of patients who had type 2 diabetes who received weight loss surgery experienced clinical remission of the disease.

    • The study is published in Circulation.