Because obesity is a significant risk factor for heart failure, weight loss can be an effective way to help prevent this life-threatening condition. Weight-loss surgery, which clinically is known as bariatric surgery, should not be the initial strategy for losing weight. But when other methods (such as decreasing calories and increasing physical activity) aren’t adequate, it is a viable option for many people.

However, weight-loss surgery is, after all, surgery, and the benefits don’t always outweigh the potential risks. If you’re considering either of the two types of bariatric procedures—gastric sleeve or gastric bypass—you’ll want to be aware of the pros and cons in order to make an informed decision about going forward.

Obesity and overweight are risk factors for several different kinds of cardiovascular disease, including high blood pressure, heart attack, atrial fibrillation, and stroke. Severe heart disease can lead to heart failure, a condition in which the heart is unable to pump as well as it should, which effectively deprives the body of sufficient oxygen-rich blood.

Even a small amount of weight loss, in the range of 5% to 7% of excess weight, can help to prevent cardiovascular disease and heart failure.

Excess weight forces the heart to work harder than normal in order to supply enough blood throughout the body. Over time, the extra workload can damage the heart and related structures, including the arteries, veins, and ventricles. The strain also harms key functions of the heart.

How Weight-Loss Surgery Impacts Heart Failure

Research bears out the potential effectiveness of bariatric procedures for treating heart failure and the conditions that contribute to it. For example, a 2020 study of nearly 40,000 people showed that those with obesity who both underwent bariatric surgery and made lifestyle adjustments (dieting and exercise) were considerably less likely to develop heart failure than those who made lifestyle changes alone.

Although an obese person may not have any symptoms of heart failure, obesity routinely is regarded as a hallmark of early-stage heart failure.

The researchers surmised the impressive effectiveness of bariatric surgery for preventing heart failure was related to the procedure’s known effects on reducing risk factors such as diabetes, high blood pressure, and atrial fibrillation.

Similarly, a 2016 study found that weight loss accomplished with bariatric surgery reduced the risk of atrial fibrillation in people being treated for severe obesity more effectively than those who made lifestyle efforts alone. Interestingly, this risk-reduction effect was largest in younger people and in people with higher blood pressures.

The extent of effectiveness of weight-loss surgery for helping to prevent heart disease has been impressive. For instance, a large study published in 2020 showed it was associated with a 40% reduction in risk of death and heart complications in patients with type 2 diabetes and obesity.

It is also worth noting that bariatric surgery can result in much greater weight loss over the short term. One study showed that by one year after surgery, patients had lost an average of 41 pounds more than those who implemented only lifestyle changes.

Types of Weight-Loss Surgery

If you’re considering weight-loss surgery, you’ll be choosing between two options:

  • Restrictive procedures: With gastric sleeve surgery, the surgeon removes about 80% of the stomach in order to create a smaller stomach, which is tubular in shape and about the size of a banana.
  • Malabsorptive procedures, such as Roux-en-Y gastric bypass, shrink the stomach and create a bypass around part of the small intestine. The bypass prevents the digestive system from absorbing some of the food a person eats. This resets the body’s appetite regulation system and speeds up the feeling of fullness after eating.

According to guidelines released in 2013 by the American Heart Association, the American College of Cardiology, and The Obesity Society, bariatric surgery may be an option for adults who have:

  • A BMI of 40 or more

OR

  • A BMI of 35 or more in addition to a health problem linked to obesity, such as type 2 diabetes, heart disease, or sleep apnea

  • A BMI of 30 or more with a serious health problem linked to obesity (only applies to gastric band surgery)

The guidelines advise primary care doctors and others caring for patients with a high BMI to try behavioral treatment with or without medications before resorting to surgery. If this effort, coupled with other diet and lifestyle measures, fails to achieve sufficient weight loss, you may be a candidate for bariatric surgery.

Risks and Prognosis

The ultimate benefit of weight-loss surgery is a reduction in the risks of heart disease and death and an improvement in quality of life. Rapid weight loss can produce significant improvements in heart failure patients, but there are caveats and risks.

Patients with extensive bypasses of the normal digestive process require careful monitoring, and also must commit to eating special foods and medications for the rest of their lives.

After gastric bypass, there is a 30% risk of nutritional deficiencies, because vitamins and minerals aren’t absorbed properly. Therefore, you will be required to take supplements for the rest of your life to protect yourself from malabsorption problems such as anemia and osteoporosis. 

In the short term, each of the bariatric surgeries have potential risks related to the procedures themselves. Those associated with gastric bypass are:

  • Bleeding (ranging from minor to severe enough to cause death)
  • Blood clots that may result in deep vein thrombosis or pulmonary embolism
  • Typical complications of general anesthesia
  • Infection—at the site of incisions, as well as in the bladder, lungs (pneumonia), or abdominal organs
  • Bowel obstruction caused by scar tissue, requiring surgical repair
  • Stroke, heart attack, limb loss, and other problems related to the operation

Possible risks for gastric banding surgery include those above, as well as:

  • Perforation of the stomach, which may cause internal leaking and require repeat surgery and intensive care, and may be fatalErosion, a rare event in which a gastric band gradually penetrates the stomach and must be surgically removedDifficulty swallowing and chest pain

Long-term success after bariatric surgery is highly dependent on compliance with a recommended diet and exercise routine. This is challenging for some, as it is a lifetime commitment.

While many people achieve rapid and significant weight loss as a result of weight-loss surgery, it is possible to regain the pounds. This can occur as early as within one to two years after surgery. Regaining too much weight can reverse the heart benefits of bariatric surgeries.