Atrial fibrillation after gastrointestinal surgery: incidence and associated risk factors

BACKGROUND: Atrial fibrillation (AF) is a common dysrhythmia that can occur after major physiological stress including surgery (postoperative AF). There are few data on postoperative AF after abdominal surgery. We set out to define the incidence of de novo postoperative AF after abdominal surgery and associated risk factors. METHODS: The Patient History Integrated Data store administrative database was interrogated for patients aged ≥65 y undergoing abdominal surgery from April 2012 to April 2014. Patients with pre-existing AF were excluded. The primary outcome was diagnosis of AF. RESULTS: Two thousand nine hundred and sixty-seven cases were included of whom 187 developed postoperative AF within 90 d (6.3%). The rate of postoperative AF varied by operation and was highest in small bowel resection (17.2%) and lowest in biliary surgery (4.8%). Median time to detection of postoperative AF was 32 d. Patients who developed postoperative AF were significantly older than those who did not develop AF (median age 75.3 y versus 72.4 y, P < 0.01). Logistic regression modeling found increasing age (odds ratio [OR] 1.03 [confidence interval {CI} 1.01-1.06], hypertension OR 1.73 [CI 1.19-2.51]), congestive cardiac failure (OR 3.04 [CI 1.88-4.92], and vascular disease OR 2.29 [CI 1.39-3.37]) were predictive of the development of postoperative AF within 30 d. The area under the curve for this model was 0.733. CONCLUSIONS: Postoperative AF affects a significant number of patients after abdominal surgery. Demographics such as history of cardiovascular disease might aid prediction of postoperative AF. Postoperative AF is mostly identified after discharge, suggesting the need for postoperative screening.