Bariatric surgery may reduce long-term atrial fibrillation risk
NASHVILLE, Tenn. — Patients with obesity who undergo bariatric surgery are less likely to develop new-onset atrial fibrillation over 8 years vs. similar patients who received medical therapy, possibly related to a greater reduction in BMI with surgery, according to study data presented here.
“We have some evidence that in patients who have been well-matched against a nonsurgical cohort, there still seems to be some reduction in the incidence of new-onset atrial fibrillation for patients who have undergone bariatric surgery,” Kevin Lynch, MD, a surgical resident in the department of surgery at University of Virginia Health System in Charlottesville, told Endocrine Today.
Obesity is associated with an increased risk for atrial fibrillation (AF), and that condition is associated with increased risk for myocardial infarction, stroke and heart failure, Lynch said during a presentation at ObesityWeek 2018. Bariatric surgery results in a high rate of long-term weight loss and is associated with amelioration of several chronic comorbidities, including hypertension, obstructive sleep apnea and type 2 diabetes.
“Recent publications have suggested that as much as 80% of diagnoses of atrial fibrillation could be attributed to obesity,” Lynch said during his presentation. “Given that, it’s not surprising that our group, as well as other groups, have been interested in studying the correlations between obesity, bariatric surgery and atrial fibrillation.”
In a retrospective data review, Lynch and colleagues analyzed data from 2,517 patients who underwent bariatric surgery at a single institution between 1985 and 2015, who were propensity score matched 1:1 to a control population of 2,517 adults with morbid obesity with outpatient appointments in a clinical data repository. Mean preoperative BMI was 47.9 kg/m² for the surgery group and 47.8 kg/m² for the medical group, and any patients with prior AF were excluded. Researchers used paired univariate analyses to compare outcomes between the two groups during a mean follow-up time of 7.9 years.
Researchers found that the incidence of AF was lower in the bariatric surgery population vs. the medical population (0.8% vs. 2.9%; P = .0001), whereas time from enrollment to development of AF did not differ between groups.
Additionally, patients undergoing surgery who developed AF also experienced a greater reduction in excess BMI then those managed medically who developed AF (P < .001).
Surgical patients who developed AF were more likely to be male, older and have hypertension or obstructive sleep apnea. Higher baseline BMI was also associated with AF in surgical patients, Lynch said.
“We were able to demonstrate a reduction in new-onset atrial fibrillation in a surgical cohort relative to a well-matched nonsurgical cohort,” he said. “Secondly, we also identified some risk factors for development for atrial fibrillation in patients undergoing bariatric surgery.”
Lynch said the study was retrospective, so it is difficult to determine causality. Additionally, there was a 6-month difference in follow-up time between the surgical and nonsurgical cohorts.
In discussion following the presentation, Philip Schauer, MD, professor of surgery at the Cleveland Clinic Lerner College of Medicine, said in the immediate postoperative period after bariatric surgery, risk for short-term AF rises, likely due to surgical stress in a vulnerable population.
“It’s an important point for all of us to recognize that, in the postoperative period, our patients are vulnerable to atrial fibrillation,” Schauer said after the presentation. “So, this long-term message is important, but in terms of perioperative medicine, it is very important to do all the things to minimize new-onset atrial fibrillation.”
Lynch said he and colleagues identified a possible “inflection point” in which the risk for AF in surgical patients decreases vs. nonsurgical controls, but there were not enough patients in the postoperative group who developed AF for observations to be characterized in a meaningful way. – by Regina Schaffer
Lynch K. A-104. Presented at: ObesityWeek 2018; Nov. 11-15, 2018; Nashville, Tenn.
For more information:
Kevin Lynch, MD, can be reached at University of Virginia School of Medicine, Department of Surgery, 3530 Hospital Drive, Charlottesville, VA 22908; email: firstname.lastname@example.org.
Disclosure: Lynch reports no relevant financial disclosures.