Weight loss surgery reduces the risk of cardiac complications and death in patients with obstructive sleep apnea and obesity

A study from the Cleveland Clinic shows that bariatric surgery in patients with obesity and moderate to severe obstructive sleep apnea is associated with a significantly lower risk of death and major cardiovascular events than in patients who have not undergone such surgery. This study was published in the Journal of the American College of Cardiology.

Ali Aminian, MD, director of the Cleveland Clinic Bariatric & Metabolic Institute and principal investigator of the MOSAIC trial, said, “Research shows that weight loss achieved through bariatric surgery is significantly associated with a 42% lower risk of major cardiovascular complications and a 37% lower risk of death in patients with obesity and moderate to severe obstructive sleep apnea.”

According to a study published in The Lancet Respiratory MedicineNearly 1 billion adults around the world suffer from obstructive sleep apnea. One of the most common risk factors for developing this sleep disorder is obesity. The Obesity Medicine Association reports that about 70% of adult patients with obstructive sleep apnea are obese.

Patients with obstructive sleep apnea – which can disrupt metabolism and lead to greater weight gain – are at increased risk of developing life-threatening conditions such as heart attack and heart failure. The MOSAIC (Metabolic surgery for OSA and Incident Cardiovascular disease) trial, led by the Cleveland Clinic, is the first of its kind to publish data on the long-term cardiovascular effects of bariatric surgery in patients with obstructive sleep apnea and obesity.

The observational study included 13,657 adult patients with a body mass index of 35–70 and the presence of moderate to severe obstructive sleep apnea (diagnosed by a sleep study test) between 2004 and 2018. The baseline clinical characteristics of 970 patients who underwent bariatric surgery were matched to 12,687 patients in the nonsurgical control group using overlap weighting methods. Follow-up ended in September 2022.

At the end of the study period, the results showed that the cumulative incidence of major adverse cardiovascular events at 10 years was 27% in the bariatric surgery group and 35.6% in the non-surgical group. A major adverse cardiovascular event is defined as the first occurrence of coronary heart events, cerebrovascular events, heart failure, atrial fibrillation, and all-cause mortality. Additional analysis shows that the cumulative incidence of all-cause mortality at 10 years was 9.1% in the bariatric surgery group and 12.5% ​​in the non-surgical group.

Steven Nissen, MD, chief academic officer of the Heart, Vascular & Thoracic Institute at the Cleveland Clinic and senior author of the study, said, “There are currently no approved drug therapies for obstructive sleep apnea. Before the MOSAIC trial, there was no therapy that could reduce the risk of serious cardiovascular events and death in patients with sleep apnea.”

After 10 years, patients in the bariatric surgery group had lost 33.2 kg and patients in the nonsurgical control group had lost 6.64 kg. Patients in the bariatric surgery group maintained their 25% weight loss for at least up to 10 years after surgery.

“Current treatment guidelines for obstructive sleep apnea recommend weight loss and lifestyle changes,” said Nancy Foldvary-Schaefer, DO, director of the Cleveland Clinic Sleep Disorders Center. “The results of the MOSAIC trial support these recommendations. However, rather than focusing solely on lifestyle changes, treating obesity with more effective and sustainable methods, such as bariatric surgery, would be needed to improve cardiovascular outcomes and survival in patients with obstructive sleep apnea and obesity.”

Dr. Aminian added, “In selected patients, bariatric surgery is a life-saving treatment. The MOSAIC trial suggests that in patients with obstructive sleep apnea, there is a dose-dependent response between the amount of weight loss and cardiovascular benefits; the greater the weight loss, the lower the risk of cardiac complications. With the advent of a new generation of obesity drugs that can provide average weight loss in the range of 15-20%, similar results are theoretically possible with medical therapies.”