American Heart Association Statement on Bariatric Surgery

This week the American Heart Association released a Scientific Statement on Bariatric Surgery and Cardiovascular Risk Factors in the latest issue of CIRCULATION.

Interestingly, the lead author and chair of the very distinguished panel of authors is our very own Paul Poirier from Laval University, Quebec City, Canada.

As the Statement points out:

“It is becoming clear that the pathophysiology of obesity is more complex than simply overeating and not exercising. In studies of bariatric surgery patients, appetite control and satiety appear to be key mechanisms for weight loss in gastric banding and gastric bypass patients, whereas calorie malabsorption plays a role in weight loss maintenance in the intestinal bypass operations.

All operations have advantages and disadvantages, with no clear evidence of one being the standard of care. There are currently no large-scale head-to head randomized trials comparing surgical procedures. Restrictive operations have a lower mortality with a lower rate of surgical and nutritional complications compared with the malabsorptive or combination operations. However, on average, restrictive operations require more frequent postoperative outpatient visits and are associated with a slower and lesser weight loss.”

The Statement provides a comprehensive and very balanced overview of the effects of bariatric surgery on cardiovascular risk factors including diabetes mellitus, hypertension, dyslipidemia, fatty liver disease, and sleep apnea and also discusses the proven benefit on cardiac morphology and function. Most importantly, the statement highlights the increasing evidence that bariatric surgery very significantly reduces the risks of dying from cardiovascular and non-cardiovascular complications of severe obesity.

The Statement also provides an overview of indications, caveats, complications and nutritional issues relevant to the care of these patients.

Relative contraindications to surgery include severe heart failure, end-stage lung disease, active malignancy, cirrhosis with portal hypertension, uncontrolled drug or alcohol dependency, and impaired intellectual capacity to understand and comply with the recommended lifestyle changes following surgery.

Finally, the statement also highlights a number of areas which require further research including a gaining better understanding of the neuroendrocrine mechanisms involved in the increased satiety, reduced hunger and metabolic changes associated with the different types of surgery as well as their impact on specific cardiovascular problems like peripheral vascular disease, strokes and malignant arrhythmias.

Thus, while the AHA statement clearly recognises the importance of bariatric surgery as a largely safe and effective treatment for patients with severe obesity, it also clearly defines the many areas in which further research needs to be conducted to better understand the mechanisms, long-term consequences, and outcomes with regard to improving cardiovascular health.

Edmonton, Alberta

Poirier P, Cornier MA, Mazzone T, Stiles S, Cummings S, Klein S, McCullough PA, Ren Fielding C, Franklin BA, & on behalf of the American Heart Association Obesity Committee of the Council on Nutrition, Physical Activity, and Metabolism (2011). Bariatric Surgery and Cardiovascular Risk Factors: A Scientific Statement From the American Heart Association. Circulation PMID: 21403092