Comparative Rates of Stroke and Rehospitalization of Atrial Fibrillation in Patients with Perioperative Atrial Fibrillation Following Major Emergency Abdominal Surgery and Patients with Non-perioperative Atrial Fibrillation.

Background: Major emergency abdominal surgery is associated with postoperative complications and high mortality. Long-term outcomes in patients with perioperative atrial fibrillation (POAF) have recently received increased attention, especially POAF in non-thoracic surgery.

Purpose: This study aimed to compare long-term AF related hospitalization and stroke in patients with POAF in relation to major emergency abdominal surgery and in patients with non-perioperative AF.

Methods: We crosslinked data from Danish nationwide registries and identified all patients who underwent major emergency abdominal surgery (2000-2018) and were diagnosed with POAF, and patients who developed AF in a non-perioperative setting. Patients with POAF were matched in a 1:5 ratio on age, sex, year of AF diagnosis and oral anticoagulation (OAC) status at the beginning of follow-up with patients with non-perioperative AF. From discharge, we examined adjusted hazard ratios (HR) of stroke using multivariable Cox regression analysis.

Results: The study population comprised 1,041 (out of 42,021 who underwent major emergency abdominal surgery) patients with POAF and 5,205 patients with non-perioperative AF. The median age was 78 years [interquartile range: 71-84] for those initiated on OAC therapy and 78 years [interquartile range: 71-85] for those not initiated on OAC therapy. During the first year of follow up, POAF was associated with similar rates of stroke as non-perioperative AF (patients initiated on OAC: HR 0.96 (95% confidence interval (CI) 0.52-1.77) and patients not initiated on OAC: HR 0.69 (95% CI 0.41-1.15).

Conclusion: POAF in relation to major emergency abdominal surgery was associated with similar rates of stroke as non-perioperative AF. These results suggest that POAF not only carry an acute burden but also a long-term burden in patients undergoing major emergency abdominal surgery.