Bariatric Surgery and the Risk of New-Onset Atrial Fibrillation in Swedish Obese Subjects

Abstract

BACKGROUND Obesity is a risk factor for atrial fibrillation, which in turn is associated with stroke, heart failure and increased all-cause mortality. OBJECTIVE We investigated whether weight loss through bariatric surgery may reduce the risk of new-onset atrial fibrillation. METHODS Swedish Obese Subjects (SOS) is a prospective matched cohort study conducted at 25 surgical departments and 480 primary healthcare centers in Sweden. The cohort was recruited between 1987 and 2001. Among 4021 obese individuals with sinus rhythm and no history of atrial fibrillation, 2000 underwent bariatric surgery (surgery group), and 2021 matched obese controls received usual care (control group). The outcome, first-time atrial fibrillation, was ascertained by crosschecking the SOS database with the Swedish National Patient Register on inpatient and outpatient diagnosis codes. RESULTS During a median follow-up of 19 years, first time atrial fibrillation occurred in 247 patients (12.4 %) in the surgical group, and in 340 (16.8 %) controls. The risk of developing atrial fibrillation was 29 % lower in the surgery group versus the control group (HR 0.71; 95 % CI 0.60-0.83; p < 0.001). Younger individuals benefited more from surgical intervention than those who were older (p-value for interaction 0.001). Also, those with a high diastolic blood pressure benefitted more from surgery than did those with a low diastolic blood pressure (p-value for interaction 0.028). CONCLUSION Compared with usual care, weight loss through bariatric surgery reduced the risk of atrial fibrillation among persons being treated for severe obesity. The risk reduction was more apparent in younger people and in those with higher blood pressure.

Body mass index, abdominal fatness, fat mass and the risk of atrial fibrillation: a systematic review and dose–response meta-analysis of prospective studies

“…The hazard ratio for the highest quintile of weight loss was 0.70 (95% CI: 0.41–1.18), thus a moderate reduction in risk cannot be excluded based on this trial. Another recent study of obese patients undergoing bariatric surgery found a reduced risk of developing atrial fibrillation with a hazard ratio of 0.71 (95% CI: 0.60–0.83) compared to the control group, providing additional evidence that adiposity is related to increased risk of atrial fibrillation [61]. Our findings of an increased risk of atrial fibrillation with higher hip circumference is somewhat in contrast to previous studies that have found an inverse association between hip circumference and cardiovascular disease [62], however, the inverse associations were only observed after further adjustment for BMI and waist circumference while none of the studies in the current meta-analysis made further adjustments for BMI and waist circumference.…”

Atrial fibrillation and type 2 diabetes: Prevalence, etiology, pathophysiology and effect of anti‐diabetic therapies

“…Bariatric surgical intervention in the Swedish Obese Subjects (SOS) cohort study, which involved 2000 surgical patients and 2021 control participants) reduced the risk of AF among individuals under treatment for severe obesity by 29% (95% CI, 0.60‐0.83), although it took several years to occur and was more apparent in younger individuals and in those with HTN. Even more impressive, the reduction occurred despite the less favourable cardiovascular risk‐factor profile at baseline in the surgical group …”

“…Even more impressive, the reduction occurred despite the less favourable cardiovascular risk-factor profile at baseline in the surgical group. 57…”

Do most patients with obesity or type 2 diabetes, and atrial fibrillation, also have undiagnosed heart failure? A critical conceptual framework for understanding mechanisms and improving diagnosis and treatment

“…However, epicardial fat is relatively resistant to weight loss regimens; thus, the modest weight loss typically seen with dietary interventions has little effect on epicardial fat deposits, and calorie restriction that leads to a small decrease in weight has minimal effects on AF, diastolic filling abnormalities and HF . In contrast, marked weight loss (by intensive calorie restriction or bariatric surgery) can decrease both the mass and inflammation of epicardial fat, and has reduced the burden of AF and restored sinus rhythm in patients with established AF in both observational studies and randomized trials . Major weight loss also reduces the risk for HF, lessens elevated cardiac filling pressures and diastolic filling abnormalities, and improves symptoms and exercise tolerance in patients with latent or overt HFpEF …”