S862 Assessment of the Relationship Between Hiatal Hernia and Incident Atrial Fibrillation

Introduction: Hiatal hernias (HH) result in protrusions of gastric mucosa into the thoracic cavity which can compress the left atrium. While this anatomical variation has been associated with increased frequency of atrial fibrillation (AF), little is known regarding the strength of the association of hiatal hernia and new-onset AF. We aimed to investigate the association of hiatal hernias and incidence of new onset AF, controlling for known risk factors and determine hernia size threshold associated with a significantly increased risk of developing AF. Methods: Patients with a reported diagnosis of HH by endoscopy performed at a tertiary care center between 2020 to 2025 were identified from the clinical endoscopy database. The diagnosis of new onset AF diagnosis within a year of hernia documentation was then identified using the International Classification of Diseases code. The association of hernia size and AF were evaluated using t test. Multi-analysis variance was performed for large (>3 cm) vs small (<3 cm) HH controlling for age, gender, alcohol, and smoking. Logistic regression was performed to assess the predictive value of hernia size for incident AF, adjusting for above risk factors. Results: We identified 2,519 patients with HH on endoscopy of which 1,108 (44%) were diagnosed with AF within 1 year. Patients with AF had larger HH than those without AF (mean 3.85 cm vs 3.27 cm, P < 0.001). Further, each additional cm increase in hernia size was associated with a 10.3% increase in the odds of AF (odds ratio [OR] = 1.10; 95% confidence interval [CI] 1.06-1.15; P < 0.001). The presence of a hernia >3 cm was associated with a higher incidence of AF (49.7% vs 40.1%; P = 0.0007). On multivariate analysis, hernia size >3 cm remained a risk factor (OR 1.30; 1.09-1.53; P = 0.003) along with age and gender. Logistical regression adjusting for factors mentioned showed an area under the curve of 0.72 with a sensitivity 74% and specificity 57%. Conclusion: The presence of larger hiatal hernia is associated with an increase incidence of AF. Future studies assessing the therapeutic value of hiatal hernia repair in patients with AF are needed.