Cardiovascular events occur less frequently after bariatric surgery
Last Sunday, an article in The New York Times described patients under 21 who undergo weight-loss surgery. The article noted that 220,00 patients undergo weight-loss surgery yearly. As anesthesiologists or intensive care physicians, our contact with patients is limited to the time when they undergo their operation or spend time in the intensive care unit. In the January 4 issue of JAMA, in their article “Bariatric Surgery and Long-term Cardiovascular Events,” Dr. Lars SjÃ¶strÃ¶m and coauthors describe cardiovascular events with a median follow-up of almost 15 years after bariatric surgery.
Patients included in the study were part of the Swedish Obese Subjects intervention study. 4047 obese patients were enrolled between 1987 and 2001. About 2000 patients underwent banding, gastroplasty or gastric bypass surgery. Control patients received lifestyle advice or no treatment.
After 20 years, the mean loss in body weight was 18% in the surgery group and 1% in the control group. There were 28 cardiovascular deaths among the 2010 patients in the surgery group and 49 among the 2037 patients in the control group. Cardiovascular events were seen in 199 patients out of the 2010 in the surgery group and in 234 patients out of the 2037 patients in the control group. When multivariable adjustments were made for baseline conditions, the reduction in both fatal cardiovascular deaths and total cardiovascular events was significant. After multivariable adjustments, fatal MI incidence, total MI incidence, number of fatal stroke events and total stroke events were significantly less in the bariatric surgery group. Within 90 days after surgery, 0.2% of surgery patients vs. 0.1% of control group patients died; 13% of those who underwent surgery had postoperative complications.
This study was not randomized, although it was matched and prospective. Absolute differences between groups, even though follow-up was long, were not great. Although the number of cardiovascular events was less after surgery, this was not correlated with weight loss. Along with the cardiovascular benefits shown in this study, other studies have shown that quality of life as well as rates of diabetes, cancer and mortality are all improved after bariatric surgery. More research is needed to determine whether the cardiovascular advantages shown in the study are related to weight loss or surgery.