Bariatric surgery can cut the incidence of heart attack, stroke or death by as much as 50 percent, according to a new study* presented here at the 28th Annual Meeting of the American Society for Metabolic & Bariatric Surgery (ASMBS). Overall, bariatric surgery was associated with a 25 to 50 percent risk reduction from either heart attack, stroke or death, a finding consistent with previous studies that compared bariatric surgery patients to non-surgical patients. An estimated 85 percent of bariatric surgery patients were living heart attack and stroke-free five-years after surgery, compared to 73 percent in the orthopaedic group and 66 percent in the gastrointestinal group.
Researchers from Greenville Hospital System (GHS) University Medical Center reviewed data of 9,140 morbidly obese patients ages 40 to 79 who had either bariatric, orthopaedic or surgery GI in South Carolina between 1996 and 2008. The orthopedic (joint replacement) and GI (hernia or gallbladder) surgery patients served as the control groups for the study because of their similar health and risk profiles. Patients had similar health status before surgery and no medical history of heart attack or stroke.
Five years after bariatric surgery, the estimated incidence of heart attack was about 50 percent less, and stroke 30 to 50 percent less when compared to the control groups. The estimated relative risk of death was also 20 to 55 percent lower in the bariatric surgery group compared to the other groups.
“Bariatric surgery has long been considered an effective treatment for morbid obesity and Type 2 diabetes, but mounting data suggests bariatric surgery can also prevent a multitude of diseases, particularly heart disease and stroke,” said John David Scott, MD, study co-author and a bariatric surgeon at GHS University Medical Center. “Clearly significant weight loss plays a role, but further research is needed to understand the relationship between the amount lost and the amount of risk reduction, and whether or not the incidence of these diseases returns to the same level if someone regains the weight.”
Obesity is a life-threatening disease that affects more than 33 percent of adults in the U.S.(1) and is a known risk factor for both heart attack and stroke, the number one and number three leading causes of death in the U.S.(2) In March, the American Heart Association (AHA) issued its first statement(3) on bariatric surgery concluding that “bariatric surgery can result in long-term weight loss and significant reductions in cardiac and other risk factors for some severely obese adults.” Rising body mass index (BMI) increases the risk of a variety of diseases and conditions including Type 2 diabetes, hypertension, cancer, sleep apnea and high cholesterol.
“The impact of bariatric surgery on both cardiovascular risk factors and events is an important area of emerging study,” said Anita Courcoulas, director of Minimally Invasive Bariatric & General Surgery at University of Pittsburgh Medical Center, and not affiliated with this study. “The authors’ findings are suggestive of an association between undergoing bariatric surgery and improved event-free survival. This relationship needs to be further explored with prospective clinical data, but still highlights the importance of understanding the broader impact of bariatric surgery on long-term outcomes.”
Bariatric surgery has been shown to be the most effective and long lasting treatment for morbid obesity and many related conditions.(4) People with morbid obesity have BMI of 40 or more, or BMI of 35 or more with an obesity-related disease such as Type 2 diabetes, heart disease or sleep apnea. Recently the FDA approved the use of an adjustable gastric band for BMI 30 and above, recognizing that there is an increase in mortality and medical complications of obesity even at this level.
According to the ASMBS, more than 15 million Americans have morbid obesity. Studies have shown patients may lose 30 to 50 percent of their excess weight 6 months after surgery and 77 percent of their excess weight as early as one year after surgery.(5)
The most common methods of bariatric surgery are laparoscopic gastric bypass and laparoscopic adjustable gastric banding (LAGB). Bariatric surgery limits the amount of food the stomach can hold, and/or limits amount of calories absorbed, by surgically reducing the stomach’s capacity to a few ounces. According to the ASMBS, more than 15 million Americans have morbid obesity.
The federal government estimated that in 2008, annual obesity-related health spending reached $147 billion,(6) double what it was a decade ago, and projects spending to rise to $344 billion each year by 2018.(7) The Agency for Healthcare Research and Quality (AHRQ) reported significant improvements in the safety of bariatric surgery due in large part to improve laparoscopic techniques and the advent of bariatric surgical centers of excellence. The risk of death from bariatric surgery is about 0.1 percent,(8) the overall likelihood of major complications is about 4 percent.(9)
Data for the study were obtained from the South Carolina Office of Research and Statistics (SCORS) database. The study included 4,747 bariatric surgery patients, 3,066 orthopaedic surgery patients and 1,327 gastrointestinal surgical patients from South Carolina.
In addition to Dr. Scott, study co-authors include Brent L. Johnson MS, Dawn W. Blackhurst DrPH, and Eric S. Bour MD, all from the GHS University Medical Center.
Material adapted from American Society for Metabolic & Bariatric Surgery.
John David Scott, MD Brent L. Johnson, MS; Dawn W. Blackhurst, DrPH; and Eric S. Bour, MD, Greenville Hospital System University Medical Center, Greenville, SC. PL-105: Does Bariatric Surgery Reduce the Risk of Major Cardiovascular Events? A Retrospective Cohort Study of Morbidly Obese Surgical Patients.
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2. Agency for Healthcare Research and Quality (AHRQ). Statistical Brief #23. Bariatric Surgery Utilization and Outcomes in 1998 and 2004. January 2007.
3. American Heart Association. “Benefits of bariatric surgery may outweigh risks for severely obese.” [Cited May 2011]. Available from: http://www.newsroom.heart.org/index.php?s=43&item=1275.
4. RA Weiner. “Indications and Principles of Metabolic Surgery.” U.S. National Library of Medicine. 2010; 81(4):379-94
5. AC Wittgrove et al. “Laparoscopic Gastric Bypass, Roux-en-Y: Technique and Results in 75 Patients With 3-30 Months Follow-up.“ Obesity Surgery. 1996. 6:500-504.
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7. K Thorpe. America’s Health Rankings. “The Future Costs of Obesity.” 2009.
8. Agency for Healthcare Research and Quality (AHRQ). Statistical Brief #23. Bariatric Surgery Utilization and Outcomes in 1998 and 2004. Jan. 2007.
9. DR Flum et al. “Perioperative Safety in the Longitudinal Assessment of Bariatric Surgery.” New England Journal of Medicine. 2009. 361:445-454.http://content.nejm.org/cgi/content/full/361/5/445